Active antenna system for radio terminal device

Abstract

A direct-connect repeater system (1000) has at least one antenna port (1002), at least one RTD / RBS port (1004) for direct, wired connection to a radio terminal device (100) or radio base station The repeater has at least one band selective repeater circuit between the at least one antenna port and the at least one RTD / RBS port.

Description

Active antenna system for radio terminal deviceTechnical Field

[0001] This invention relates to an active antenna system for a radio terminal device (RTD) operating on a wireless telecommunication network. Specifically, this invention relates to an antenna system that utilizes one or more amplify and forward RF repeaters, which directly connect to either: a radio terminal device in order to boost the downlink channel signal strength as such to optimize the downlink service performance (radio base station to radio terminal device), the uplink channel signal strength as such to optimize the uplink service performance (radio terminal device to radio base station) or to control the radio terminal device radiation emissions according to the antenna selected, or a radio base station in order to boost both the downlink and uplink channel paths as such to optimize a Distributed Antenna System service performance (radio terminal device to DAS to radio base station) of a wireless telecommunication network.Background Art

[0002] To address weak or poor wireless connections, antenna systems on radio terminal devices are often utilized. These antenna systems may be either embedded within the device or externally attached. A radio terminal device (RTD) is defined herein as a device that connects with at least one network radio base station (RBS) to facilitate data transfer via radio signal transmission. Examples of radio terminal devices that may incorporate such antennas and operate on wireless telecommunication networks include modem / routers, customer premises equipment (CPE), cellular phones, smartphones, laptops, tablets, access points (APs), Internet of Things (loT) devices, and other similar radio network terminal devices.

[0003] In modern wireless technology networks such as LTE and 5G, the modem used in radio terminal devices is commonly referred to as user equipment (UE). However, those skilled in the art may also refer to it as a mobile station (MS), a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communications device, a remote device, a mobile subscriber station, an access terminal (AT), a mobile terminal, a wireless terminal, a remote terminal, a handset, a terminal, a user agent, a mobile client, a client, or other suitable terminology. When thesemodems require external antennas, they are typically connected via a physical coaxial link between the antenna and the modem within the radio terminal device.

[0004] A radio terminal device may also be used to re-transmit RBS signals in a wired or wireless manner, in the initial form of the signal or other forms, to offer service to at least one end user. In this mode, the radio terminal device can serve as an intermediary between the RBS and the end user. Alternatively, the radio terminal device may be the endpoint itself (for example, the radio terminal device may be any device using the network connection to browse the internet). Examples of intermediate devices can be wireless modem / routers, signal repeaters and boosters, backhauling systems and the like.

[0005] An example of a smartphone used as an intermediate device is when a smartphone is set in wireless hotspot mode to offer WiFi (TM) coverage to other smartphones, tablets, laptops and other radio terminal devices in range. Another example is when a radio repeater / booster is used as an intermediate device in order to further re-transmit the received RBS signals (donor RBS) using a single re-transmitting antenna or a distributed antenna system to offer (i.e., indoor) coverage to other radio terminal devices in range. A further example is when one or more cellular chip(s) / modem(s) is configured with a router and optionally with an internet bonding / bundling device to utilize the initial RBS signals in order to operate as a backhauling system for a plurality of indoor radio units such as Ericsson's radio dots (TM) or similar to offer wireless network coverage to a "hotspot".

[0006] By "hotspot" we mean a predefined geographical area containing multiple end users that are requesting service directly from a wireless telecommunication network or via an intermediary device. Hotspots can be static (indoor or outdoor) or moving in the wireless telecommunication network coverage footprint. Examples of static indoor hotspots are homes, hotels, factories, in-building coffee shops, clubs, restaurants and the like. Examples of static outdoor hotspots are stadiums, beaches, outdoor coffee shops, clubs, restaurants and the like. Examples of moving hotspots are ships, buses, trains, tracks, cars and the like.

[0007] A SISO (Single Input Single Output) radio terminal device (RTD) 120 connected via a coaxial port 1 10 with an external antenna 100 to a wireless telecommunication network radio base station (RBS) 130 is shown in Figure 1 a. External antennas in principle (due to the designed dimensions), have better electrical characteristics than their embedded equivalent therefore, it is known that external antennas have improved connectivity performance compared to embedded antennas. Figures 1 b and 1 c show a MIMO (MultipleInput Multiple Output) on a two data stream (two antennas 100') and four data stream (four antennas 100") configuration respectively. Radio terminal devices 120', 120" using higher order MIMO utilize a higher number of antennas with an aim to utilize more data streams as such to further improve the service performance of a wireless telecommunication network.

[0008] External antennas of omnidirectional or directional radiation patterns can be deployed on the radio terminal devices. Such antennas are off-the-shelf and can be selected out of a plurality. Multiple external antennas are required to be deployed at predetermined E-plane polarization or X-multiple spacing in order that signal transmissions and receptions from each antenna are uncorrelated for MIMO to perform. Antennas are required to support the frequency bands of operation of the serving radio base station 130 of the wireless telecommunication network and the radio terminal device in use. Radio terminal devices that operate with carrier aggregation and / or at multiple frequency bands require broadband antenna systems when a single port is offered for antenna connectivity (combined / multiplexed at the radio terminal device).

[0009] Teltonika (TM) RUTX50 is a modem-router designed to provide WiFi connectivity to a hotspot by establishing a reliable connection to LTE and 5G networks. It is a four data stream MIMO radio terminal device that supports carrier aggregation across multiple LTE and 5G frequency bands. To fully utilize its MIMO and carrier aggregation capabilities, the RUTX50 requires four broadband antennas, which are typically omnidirectional and directly connect to the device's external antenna ports. While these omnidirectional antennas support multiple frequency bands and carrier aggregation, they generally have low gain and MIMO efficiency (de-correlation / de-coupling) as well as lacking directivity. As a result, the radio link may suffer from weak signal strength-especially in indoor or low-elevation installations-and increased interference from nearby base stations. This combination of low received signal strength and high interference degrades the signal to interference and noise ratio (SINR), negatively impacting the wireless connection's performance.

[0010] Beyond the RUTX50, other radio terminal devices (RTDs) serve different purposes, each requiring efficient network connectivity. For example, industrial loT gateways connect sensors and remote monitoring systems, mobile broadband modems provide high-speed data access for vehicles, and fixed wireless access (FWA) CPEs deliver broadband internet to homes and businesses. Each of these devices may have distinct applications, necessitating high performance wireless connectivity.

[0011] A wireless connection may achieve from the network maximum speeds and data throughputs when the signal to interference and noise ratio (SI N R) of the radio links formed between the radio base station and the radio terminal devices in use are capable of supporting the highest modulation and coding scheme (MCS) of the technology they operate. In order forthe radio base station signal to be demodulated by the receiver of the radio terminal device (criterion for achieving connectivity), it needs to be greater in power than the sensitivity of the receiver (i.e. the minimum power that the receiver can distinguish the signal from the noise and decode it).

[0012] The sensitivity of a receiver (or its noise floor) is equal to FKTB, where F is the receiver's noise factor (linear), K is the Boltzmann constant, T is the temperature in Kelvin and B is the receiver's operating bandwidth in Hertz). In an exemplary scenario, the receiver thermal noise power level operating on a 20MHz channel bandwidth at room temperature (kTB for T = 290° Kelvin and B = 20MHz) is -100.96dBm (logarithmic). Therefore, the sensitivity of our exemplary receiver would be -100.96dBm plus the noise figure (in dB) introduced by the receiver circuitry itself.

[0013] In a model LTE technology wireless telecommunication network of 20MHz channel bandwidth, 29 different modulation and coding schemes (MCS) are supported, each offered at wireless connections of different minimum signal to interference and noise ratios (LTE / 5G or similar technologies that operate / utilize radio link adaptation features). The highest modulation and coding scheme - MCS - is attributed to radio links established between radio base stations and radio terminal devices that meet corresponding conditions of signal strength, interference and noise levels.

[0014] In the table above, it is observed that when the receiver experiences a minimum signal reception of -72.6 dBm and an SINR level of at least 24.87 dB, the network supports the highest Modulation and Coding Scheme Index (MCSI 28). Under these conditions, in our model LTE technology with a 20 MHz channel bandwidth, the radio terminal device can achieve total service bit rates of 75.38 Mbps. It should be noted that when the channel bandwidth increases-such as in the case of carrier aggregation or multi-frequency band operation-the same modulation and coding scheme (MCSI 28) is expected to provide total service bit rates of 150.76 Mbps for 40 MHz, 226.14 Mbps for 60 MHz, and 301 .52 Mbps for 80 MHz channel bandwidths, respectively.

[0015] Additionally, it is observed that when the receiver operates with a 4 data stream MIMO system that is fully uncorrelated, with an Envelope Correlation Coefficient (ECC) of 0 (MIMO Rank 4), and utilizing the aforementioned MCSI 28, the total service bit rates in arich multipath environment are expected to be 301.52 Mbps for a 20 MHz channel bandwidth, 603.04 Mbps for 40 MHz, 904.56 Mbps for 60 MHz, and 1206.08 Mbps for a 80 MHz channel bandwidth.

[0016] However, when the receiver experiences a minimum signal reception of -101 dBm and an SINR level of at least -3.98 dB, the network supports only the lowest modulation and coding scheme (MCSI 0). Under these conditions, our model LTE technology with a 20 MHz channel bandwidth will offer the radio terminal device total service bit rates of 2.79 Mbps. For wider channel bandwidths, the corresponding bit rates are 5.58 Mbps for 40 MHz, 8.37 Mbps for 60 MHz, and 1 1.16 Mbps for 80 MHz. If the received signal level falls below -101 dBm and / or the SINR drops below -3.98 dB, the wireless telecommunication network ceases to provide service to the radio terminal device.

[0017] Under such poor radio conditions, MIMO performance is also significantly degraded. When the received signal level is at -101 dBm with an SINR of -3.98 dB, the multipath diversity benefits of MIMO are severely diminished due to the high interference and low signal power. In this scenario, the likelihood of achieving a high-rank MIMO transmission (such as Rank 4) is extremely low, as the channel conditions do not support sufficiently independent spatial streams. Instead, the network will likely fall back to a lower MIMO rank, such as Rank 1 or 2, where spatial multiplexing is no longer effective. As a result, even in a 4 data stream MIMO system, the expected total service bit rates under these conditions will remain close to the single-stream performance, i.e. total service bit rates of 2.79 Mbps on a 20 MHz channel bandwidth.

[0018] The above discussion highlights the substantial variation in service speeds-despite using the same network resources (spectrum and channel bandwidth)-due to the impact of radio link performance. Knowing that radio link performance depends solely on the levels of signal to interference and noise ratio (SINR), the levels of the received signal power from the serving radio base station, the levels of the received interference power (assuming a fine regulated market we should not account interference from external sources) and the noise introduced by the receiver circuitry of the radio terminal device itself.

[0019] Therefore, to ensure a high performance radio link connection between the exemplary Teltonika™ RUTX50 radio terminal device and an LTE technology radio base station-achieving wireless connectivity at the highest modulation and coding scheme (MCS) offered by the network-priority must be given to maximizing the received signalstrength while minimizing interference and noise power. For a 20 MHz channel bandwidth, the receiver sensitivity is at least equal to the receiver's thermal noise power, which is calculated to be -100.96 dBm (assuming ideal conditions where both interference and receiver system noise contributions are zero). To achieve optimal network connectivity with a signal to interference and noise ratio (SINR) of 25 dB-sufficient to support the highest MCS index-the received signal strength at the radio terminal device must be at least 25 dB higher than the receiver sensitivity, resulting in a minimum signal level of -75.96 dBm.

[0020] However, this calculation assumes a perfect receiver with only thermal noise considered. In real-world conditions, where interference is typically present and receiver circuitry introduces additional noise, the required received signal strength at the radio terminal device becomes even more demanding. The combined effect of interference and non-ideal receiver noise increases the noise floor, further raising the signal strength threshold necessary to achieve the highest MCS index and thus maximize data throughput rates.

[0021] It has to be noted at this point that on average for every single dB less, the referenced optimum received signal strength level drags the MCS index (0-28) to a lower level, offering the wireless connection reduced code rates (spectrum efficiency) directly resulting in a drop of the radio terminal device total service bit rate. Adding to the 'ideal' sensitivity of the radio terminal device receiver (which is -100.96dBm for 20MHz channel bandwidth) the noise figure of a typical receiver circuitry (for example a 3dB noise figure - NF), the 'actual' receiver sensitivity will become -97.96dBm (-100.96dBm + 3dB = - 97.96dBm). Therefore, in order to achieve the required 25dB signal to interference and noise ratio (SINR = 25dB), assuming an interference free environment, the needed received signal strength at the radio terminal device should be at least -72.96dBm. Taking into account that most of the radio terminal devices, as our exemplary Teltonika (TM) RUTX50, are located indoors we expect that rarely the device will achieve such received signal strength levels, especially with the low gain antennas that these radio terminal devices are equipped. This is undesired.Prior Art Amplify and Forward (AF) Repeaters or "off-air" RF Repeaters

[0022] An option to boost the radio signal strength at the radio terminal device is to use an amplify and forward (AF) bi-directional (or "two-way") "off-air" RF repeater. An "off-air"repeater, also known as an RF signal booster or RF signal amplifier, is a device designed to improve signal strength reception in areas with weak or unreliable wireless coverage.

[0023] An example "off-air" repeater 150 is shown schematically in Figure 1 d. It consists of three main components which namely are an external or donor antenna 152, a bidirectional signal amplifier 154 and an internal or service antenna 156. The external antenna 152 is placed outside a physical barrier of a building or vehicle (see wall 158 separating interior 160 from exterior 162) to capture the existing weak radio signal from the RBS 130 to be re-transmitted. This antenna 152 is usually mounted on the roof or a high point outdoors, as such to maximize signal reception and to provide the required isolation from the service antenna 156.

[0024] The captured radio base station signal from the donor antenna (downlink) and the captured radio terminal device signal from the service antenna (uplink) are directed to the bi-directional (downlink and uplink) signal amplifier system. The amplifier system boosts the signal's strength of both downlink and uplink significantly (as such to compensate the air interface or "off-air" RF signal losses), making them stronger and more reliable within its intended coverage area.

[0025] The internal service antenna 156 is positioned inside the building or vehicle to retransmit the downlink amplified signal to the wireless device(s) within its range and the uplink amplified signal towards the donor radio base station. Using an amplify and forward (AF) bi-directional (or "two-way", downlink and uplink) "off-air" RF repeater allows smartphones, CPEs, modem / routers, loT and other radio terminal devices such as Teltonika (TM) RUTX50 to connect to a stronger signal, resulting in improved network accessibility (but not necessarily on improved network speeds and data throughput rates).

[0026] There are several problems with known two-way amplify and forward (AF) "off-air" repeaters that cannot offer a radio terminal device with improved network speeds and data throughput rates. Some of the problems are outlined below:• MIMO efficiency and performance;• Carrier Aggregation (CA) or multi-frequency band operation; and,Donor and service antenna isolation and de-coupling.

[0027] "Off-air" repeaters, although offering improved network accessibility (particularly useful in areas with poor wireless coverage, such as rural locations, remote areas, or buildings with thick walls that can totally block signals), are not intended to be used in order that a radio terminal device achieves high network speed and data throughput rate connectivity. On the contrary, although the use of an "off-air" repeater will boost radio signal reception, as such the required received signal strength at the radio terminal device of our previous example to match the targeted threshold, the network performance is expected to degrade. The main reason for such degradation is the fact that amplify and forward (AF) bi-directional (or "two-way") "off-air" RF repeaters do not optimally utilize MIMO technology and carrier aggregation (or multi-frequency band operation), both of which feature prominently in modern 4G, 5G and other wireless network implementations in order to offer increased radio base station capacity and broadband experience.

[0028] Further, since "off-air" RF repeaters boost any radio signal within their frequency band of operation (as received at their input), depending on the donor antenna type deployed (i.e. omnidirectional), any interference signals present competing with the desired signal for re-transmission will be equally boosted (depending on the received signal strength levels of the dominant radio base station and the interference radio base station(s) at the antenna, the SINR levels at the radio terminal device after the RF repeater re-transmission are accordingly degraded).

[0029] Turning on the Teltonika's (TM) RUTX50 radio terminal device, we may see that the external antennas recommended by Teltonika for this device are of omnidirectional radiation pattern, meaning that for small difference on the received signal strength levels from both the dominant radio base station and the interference radio base station(s), the signal to interference and noise ratio will be significantly impacted, resulting to radio terminal device service degradation. Due to the aforementioned reasons, collecting network signals using omnidirectional antennas and using known RF repeaters in conjunction with such antennas is clearly undesirable.

[0030] It will be noted that the applicant's previous patent applications such as those described in published WO 2016 / 087431 A1 , WO 2024 / 01 7902 A1 and WO 2024 / 246242 A1 , which are hereby incorporated by reference where permitted, deal with this problem by reducing the received signal strength levels of the interference radio base station(s) directly at the antenna, especially on moving vehicles, by replacing the omnidirectionalantenna with a directional antenna targeting towards one (or more) selected radio base station direction.MIMO problems with prior art "off-air" RF repeaters

[0031] A single RF repeater significantly degrades MIMO performance by eliminating spatial decorrelation. This occurs because RF repeaters amplify and retransmit signals without generating independent multipath components, which are essential for maintaining multiple spatial data streams. Unlike a true MIMO system, which relies on multiple transmit and receive antennas to create independent paths, an RF repeater typically relays the same signal across all its outputs, collapsing the spatial diversity required for high-rank MIMO operation.

[0032] To successfully retransmit multiple independent data streams, multiple, independent RF repeaters would be required. Specifically, a two data stream MIMO system would require at least two independent RF repeaters, while a four data stream MIMO system would require at least four RF repeaters. However, even with such configurations, full MIMO performance cannot be fully restored unless each repeater maintains spatial separation and introduces independent propagation paths to decorrelate the signals. This is difficult to achieve in practical deployments.

[0033] MIMO performance relies on maintaining signal decorrelation at both the outdoor and indoor levels. If the received signals are already decorrelated from multiple donor antennas outdoors and from multiple service antennas indoors, using RF repeaters may reduce overall decorrelation instead of maintaining it. Mathematically, the total signal decorrelation can be approximated as:Total Decorrelation = Outdoor Decorrelation x Indoor Decorrelation.

[0034] For example, if outdoor decorrelation is 0.8 and indoor decorrelation is 0.8, then the combined decorrelation is 0.8 x 0.8 = 0.64, which is lower than the 0.8 achievable with either outdoor or indoor decorrelation alone. Since MIMO speed scales with MIMO rank, reduced decorrelation leads to lower rank and diminished performance. Instead of the expected 1.8x speed gain from 0.8 decorrelation, the combined scenario would only provide a 1 ,64x speed gain, reducing the overall throughput improvement.

[0035] Maintaining high MIMO rank is crucial for maximizing network speeds and data throughput. MIMO rank is determined by both the channel environment (decorrelation,ECC, SINR) and the number of spatial streams supported. Deploying RF repeaters without carefully preserving spatial independence will degrade MIMO performance, leading to lower throughput and suboptimal wireless connectivity. MIMO performance degradation is clearly undesirable when trying to achieve optimum radio terminal device connectivity of high network speeds and data throughput rates.Carrier Aggregation (CA) problems with prior art "off-air" RF repeaters

[0036] A single "off-air" RF repeater is not capable of supporting carrier aggregation (CA) or multi-frequency band operation. Most "off-air" RF repeaters have limited capability to operate across multiple frequency bands, and those that do are prohibitively expensive for practical applications. In general, one band-selective repeater is required per frequency band, meaning that three band-selective repeaters are required to support three frequency bands, six band-selective repeaters are required to support six frequency bands, while multi band-selective repeaters are required to support multi frequency bands.

[0037] Band selection in "off-air" RF repeaters is achieved by incorporating band-pass filters before the amplifiers, ensuring that only signals within the desired frequency band are amplified. For example, an LTE Band 1 (B 1 ) FDD repeater will filter and amplify only a 120 MHz bandwidth, specifically:• 60 MHz in the uplink (1920 MHz - 1980 MHz)• 60 MHz in the downlink (21 10 MHz - 21 70 MHz)

[0038] Beyond the required number of "off-air" repeaters, an equivalent number of donor and service antennas is also necessary. Typically, each frequency band requires a separate narrowband antenna to effectively receive and retransmit signals. Some configurations may attempt to utilize multi-band donor and service antennas, but these require costly RF cavity duplexers or multiplexers to manage high RF output power while maintaining proper isolation between bands.

[0039] Carrier aggregation is essential for boosting network speeds and data throughput, as it enables the aggregation of multiple frequency bands (e.g., LTE B1 / B3 / B7 in a 3CA setup). Devices supporting carrier aggregation experience significantly higher data rates, depending on the number of aggregated bands and their respective bandwidths. Failureto support CA or multi-band operation severely limits network performance and device connectivity.

[0040] Moreover, supporting both carrier aggregation and MIMO on an RF repeater introduces additional complexity and significantly increases costs. Achieving optimal performance requires advanced filtering, precise synchronization, and a scalable antenna system, making it a highly expensive and challenging solution for practical deployments.Antenna isolation problems with prior art "off-air" RF repeaters

[0041] The installation of amplify-and-forward (AF) bi-directional (or "two-way") "off-air" RF repeaters requires specialized personnel to ensure proper positioning of the donor and service antennas. A critical consideration in RF repeater deployment is donor / service antenna isolation (decoupling), which prevents oscillation and signal disruption.

[0042] "Off-air" RF repeaters significantly amplify signals to extend coverage. However, if the donor and service antennas are improperly aligned, too close to each other, or unobstructed, the amplified signal from the service antenna can feed back into the donor antenna, creating an oscillation loop. This feedback can cause severe interference, degrading network performance.

[0043] To mitigate this issue, antenna decoupling techniques must be applied. The most effective method is physical separation between the donor and service antennas, using either distance or RF-blocking obstacles to prevent signal feedback. The required separation distance depends on several factors, including repeater system gain, output power, operating frequency bands, and environmental conditions.

[0044] Proper antenna placement often requires specialized tools and expertise to optimize performance. In some environments, such as in-vehicle installations, achieving adequate antenna isolation may be physically challenging or impractical. Due to the complexity of installation and the limitations of antenna decoupling, "off-air" RF repeaters may not always be the ideal solution for ensuring reliable signal enhancement.

[0045] Further, it should be noted herein that when aiming to properly install directional donor and service antennas that support both carrier aggregation and MIMO technology makes things even more complicated. Installation complexity of multiple directional donor and service antennas, that need to be isolated to each other and also positioned atpredetermined E-plane polarizations or X-multiple spacings such that signal transmissions and receptions of each is uncorrelated for MIMO to perform (low ECC for high MIMO rank), is a complex and specialised operation.Distributed Antenna Systems (DAS)

[0046] Figure 1 e shows a distributed antenna system (DAS) being directly connected (wired) to a femto-, pico-, micro-RBS or a high power bi-directional "off-air" RE repeater 130' of high output power on the downlink channel path. Such a configuration may be in place, for example, within a shopping mall, an industrial site or a Ro-Pax ferry. The femto-, pico-, micro-RBS or high power "off-air" RE repeater 130' is directly connected to a plurality of splitters 164i - 164N, each of which is connected to a respective service antenna 1661 - 166N.

[0047] The service antenna 1661 connected to splitter 164i experiences downlink and uplink bi-directional loses of i.e. 3dB or more. The service antenna 1664connected to splitter 1644experiences even higher downlink and uplink bi-directional loses. Some of the antennas are close to the RBS / "off-air" repeater 130', meaning RE losses through the coaxial cabling is relatively low. For others, it is high, and thus the intended coverage area of these service antennas (especially for the high pathloss service antennas) experience service footprints of low network speeds and high throughput rates for the exact same reasons that have been identified on the previous discussion.

[0048] It is the purpose of the present invention to use an RF repeater in order to achieve an inexpensive, radio terminal device connectivity of high network speeds and data throughput rates, by fully utilizing MIMO and carrier aggregation technologies without encountering (where applicable) antenna isolation or de-coupling problems even in challenging environments.Summary of invention

[0049] According to a first aspect of the invention there is provided a repeater system comprising: at least one antenna port; at least one radio terminal device / radio base station port for direct, wired connection to a radio terminal device (RTD) or radio base station (RBS);at least one band selective repeater circuit between the at least one antenna port and the at least one radio terminal device / radio base station port.

[0050] Each band selective repeater circuit has an uplink channel path and a downlink channel path. The channel paths may have different gains depending on the application and requirements of the repeater system as will be described below.

[0051] In one embodiment, each repeater circuit has net zero gain on one channel path. By "net zero" we mean that the signal strength at the output port is the same as that at the input port. For example net zero on the uplink channel path means that the antenna port sees the same signal strength as transmitted from the radio terminal device at the radio terminal device port. It will be understood that "zero" and "same" are used within normal operating tolerances, and may not be exactly zero, or exactly the same, but instead functionally identical.

[0052] Advantageously, by using net zero gain on the uplink channel path, the power class of the radio terminal device does not change, therefore the repeater of the present invention will not cause regulation violations related to maximum radio terminal device transmit power limits. This ensures compliance with standards and regulatory requirements on the uplink channel path while still improving the radio link performance on the downlink channel path.

[0053] Alternatively, by using net zero gain on the downlink channel path, the power class of the radio base station does not change, therefore the repeater of the present invention will not cause regulation violations related to maximum radio base station transmit power limits. This ensures compliance with standards and regulatory requirements on the downlink channel path while still improving the radio link performance on the uplink channel path.

[0054] The International Commission on Non-Ionizing Radiation Protection (ICNIRP) sets guidelines to protect against potential health effects from exposure to electromagnetic fields (EMFs), including those used in sub-6 GHz and mmWave LTE and 5G technologies. In their 2020 guidelines, ICNIRP specifies basic restrictions and reference levels for exposure to radiofrequency EMFs in the range of 100 kHz to 300 GHz, covering the frequencies used by sub-6 GHz and mmWave LTE and 5G technologies.

[0055] In particular, the Federal Communications Commission (FCC), the national regulator in USA, establishes limits to ensure that radio terminal devices operate safely for both the general population (Uncontrolled Exposure) and occupational (Controlled Exposure). Key aspects of these regulations include:1. Specific Absorption Rate (SAR) Limits:

[0056] The FCC sets SAR limits to protect users from excessive exposure to radiofrequency (RF) energy:• General Population / Uncontrolled Exposure: The SAR limit is 1 .6 watts per kilogram (W / kg), averaged over 1 gram of tissue. This applies to devices used by the general public without specialized training.• Occupational / Controlled Exposure: For occupational settings where users are aware of RF exposure and can exercise control over it, the SAR limit is 8 W / kg, averaged over 1 gram of tissue.

[0057] Manufacturers must ensure that their devices comply with these SAR limits before they can be marketed or sold in the United States.2. Transmitter Power Limits

[0058] The FCC specifies maximum transmitter power levels for different frequency bands to prevent interference:• U-NII Bands (Unlicensed National Information Infrastructure): These bands are commonly used for Wi-Fi and other unlicensed devices:• U-NII-1 (5.150-5.250 GHz): Maximum conducted output power is 50 mW (1 7 dBm), with a maximum EIRP of 200 mW (23 dBm).• U-NII-2A (5.250-5.350 GHz) and U-NII-2C (5.470-5.725 GHz): Maximum conducted output power is 250 mW (24 dBm), with a maximum EIRP of 1 W (30 dBm).U-NII-3 (5.725-5.850 GHz): Maximum conducted output power is 1 W (30 dBm), with a maximum EIRP of 4 W (36 dBm).

[0059] These limits are designed to balance device performance with the need to minimize potential interference with other spectrum users.3. Power Spectral Density (PSD) Limits

[0060] The FCC also imposes PSD limits to control the power distribution across the transmission bandwidth:• U-NII Devices: For example, in the U-NII-1 band, the PSD limit is 4 dBm per MHz.

[0061] Compliance with PSD limits helps prevent interference by ensuring that the transmitted power is spread appropriately across the available spectrum.

[0062] The present invention provides a net zero gain repeater in at least one channel path (uplink and / or downlink) having the following advantages.

[0063] The aforementioned problems of the prior art are mitigated by the direct connection of one or more repeaters to the radio terminal device (or modem). By direct connection, we mean that the repeater does not rely on a service antenna to establish an "off-air" link with the radio terminal device. Instead, it is connected via a wired interface, such as a coaxial cable.

[0064] A key advantage of this direct connection is that it eliminates the need for service antennas, thereby removing the requirement for isolation and decoupling measures that typically involve maintaining a specific distance or path loss between the donor and service antennas. This significantly simplifies deployment and enhances efficiency. Furthermore, this approach enables the practical use of RF repeaters in compact or mobile environments, such as cars, buses, trucks, RVs, train wagons, and small boats, where traditional repeater configurations would otherwise face challenges due to isolation constraints.

[0065] The repeater donor antennas are selected to be broadband to ensure carrier aggregation or multi-frequency band operation. The antennas are "matched" to the multiple operating frequency bands (broadband) required by the radio terminal device to perform. Suitable broadband antennas for the application are Log-Periodic, TEM-Horn, Vivaldi-Horn, Biconical and the like. Using the appropriate number of band selective repeaters i.e. per desired frequency band and for both downlink and uplink channels, multiplexed on a single connection port on the broadband antenna side and on a singleconnection port on the radio terminal device side one achieves the required RF repeater carrier aggregation or multi-frequency band operation.

[0066] Using the appropriate number of identical multiplexed band selective repeaters along with the desired MIMO configuration antennas (one per desired data stream positioned at predetermined E-plane polarizations or X-multiple spacings) and identical coaxial cables for consistent phase and amplitude characteristics connecting the antennas with the multiplexed band selective repeaters and the multiplexed band selective repeaters with the radio terminal device, the required multiple independent decorrelated / decoupled data streams of MIMO technology can be satisfied (either outdoor or indoor depending on where the donor antennas would be located).

[0067] Therefore, as with the isolation / de-coupling problem, the MIMO and carrier aggregation / multi-band operation of RF repeater is also tackled, theoretically allowing for optimum radio terminal device connectivity achieving high network speeds and data throughput rates.

[0068] In summary:• By directly connecting the RF repeaters of the present invention to the radio terminal device antenna connection port the donor-service antenna isolation problem of the prior art "off-air" RF repeaters disappears.• By using the appropriate number of multiplexed band selective repeaters i.e. per desired frequency band and for both downlink and uplink channels, one achieves the required support of carrier aggregation or multi-frequency band operation; and,• By using multiple identical multiplexed band selective repeaters and connection cables along with the desired MIMO configuration antennas the required multiple independent data streams of MIMO technology can be satisfied;

[0069] It has to be noted at this point that since with the direct connection of the radio terminal device to the RF repeater we are not utilizing the service antenna, the "off-air" RF pathlosses between the RF repeater and the radio terminal device disappear, resulting in link budgets that require repeaters of low gain and output power. This has direct impact on the repeater's costs (i.e. low cost of duplexer and multiplexer filters, such as surface acousticwave - SAW and bulk acoustic wave - BAW filters, among others), which make MIMO and carrier aggregation or multi-frequency band configurations inexpensive to deploy.

[0070] Therefore, the present invention mitigates the poor radio link connection problem that radio terminal devices located indoor or at remote / rural locations present, achieving wireless connectivity performance to support high network speeds and high throughput rates inexpensively, without altering the radio terminal device power category or class. That said, the implementation of a repeater for direct connection to the radio terminal device can still cause several problems that are also addressed by the present invention.Problems with directly connecting RF repeaters to the radio terminal device

[0071] It will be appreciated that the direct connection repeater of the present invention, may exhibit problems in certain situations as will be outlined below. It is a further aim of the present invention to overcome such problems.

[0072] We know that the radio terminal device receiver (downlink channel path) has RF circuitry that consists of low-noise-amplifiers (LNAs) that may amplify the incoming radio base station signals from the RF repeater without distortion (compression or saturation) only when those do not exceed a predefined power strength. We also know that in the first aspect of the present invention, the RF repeater at its uplink channel path preferably has RF circuitry that consists of power amplifiers that may amplify and forward the transmitted signals from the radio terminal device without distortion (compression or saturation) only when those do not exceed a predefined power strength. It is imperative that all amplifiers on a radio communication system should operate in a linear fashion.

[0073] Linearity, in this context, refers to the amplifier's ability to faithfully reproduce its input signals without introducing non-linear distortions, due to compression or saturation. Compression occurs when the amplifier reaches its maximum capacity to amplify signals, resulting in a compression of the signal amplitudes and potential loss of information. Saturation, on the other hand, is a condition where the amplifier is pushed to its upper limit, causing distortion and the generation of harmonics.

[0074] To ensure optimal system functionality, maintaining the quality of the re-transmitted signals (on both downlink and uplink channel paths) is of paramount importance.

[0075] When directly connecting an RF repeater to a radio terminal device, the received downlink signal power (after amplification) should not exceed the radio terminal deviceLNA maximum input power. The exact maximum input power an LTE or 5G radio terminal device can handle without causing compression or saturation of its LNA depends on the design of its receiver front-end (modem specific). However, the maximum usable input power before the modem's LNA starts saturating is typically around -25dBm to -20dBm. The 1 dB compression point (P1 dB) of LNA is often in the range of -20dBm to -15dBm. Beyond this point, the LNA starts exhibiting nonlinear behavior. The absolute maximum input power before potential damage is usually OdBm to +10dBm, but operation at this level is undesirable as it causes severe distortion and may activate receiver protection circuits. Signals stronger than -30dBm at the antenna port of the radio terminal device can already pose a risk of LNA compression, especially in high-gain MIMO receivers which are deployed from radio terminal devices aiming high network speeds and data throughput rates.

[0076] To prevent the radio terminal device LNA compression or saturation when directly connecting an RF repeater (downlink channel path) one needs to ensure that the RF repeater output power will never exceed the radio terminal device specified input power levels according to the design of its receiver front-end (e.g. -30dBm on MIMO radio terminal devices, -25dBm or less on others). This is especially the case on moving vehicles where the received signal strength fluctuates due to changing distances from base stations, signal reflections, and interference, as such RF repeater output power thresholds should always be considered.

[0077] It is an aim of the present invention to overcome these problems.

[0078] According to a second aspect of the invention, there is provided an apparatus for the protection of the low noise amplifiers of a radio terminal device when is directly connected on an RF repeater, the apparatus comprising: an RF repeater directly connected on a radio terminal device comprising an input, and output, at least one amplifier circuit between the input and the output and at least one bypass circuit configured to selectively bypass the at least one amplifier circuit; a controller comprising a power detector configured to detect a power level from the input to the at least one amplifier circuit, wherein the controller is configured to switch between the at least one amplifier circuit and the at least one amplifier circuit dependent on the power level.

[0079] The second aspect may be used in downlink and I or uplink channel paths as will be explained below.

[0080] Advantageously, to ensure that the repeater for direct connection does not exceed the P1 dB compression point of the radio terminal device receiver front-end (MODEMpids), especially in challenging applications such as on moving vehicles, one needs to consider applying output power limiting mechanisms to the RF repeater downlink channel path. The RF repeater should be designed to restrict its maximum output power level (REPEATERPout) towards the radio terminal device receiver front-end. Ensuring that the radio terminal device does not experience saturation or compression (REPEATERpout < MODEMpids), an amplifier bypass circuitry should be applied preventing the modem from overdriving (REPEATERpout > MODEM pids) under high received signal strength conditions from the radio base station. By applying these measures, the radio terminal device can function efficiently the downlink channel path at all times, supporting stable communication without causing overload or compression of its receiver front-end.

[0081] Atthe same time, when directly connecting a radio terminal device to an RF repeater (uplink channel path), we should ensure that the transmitted uplink signal power should not exceed the repeater's power amplifier maximum input (PA idB-iNPui) and output P1 dB compression point (PApidB-ouTPui). The maximum input RF power an RF repeater can handle before its power amplifier enters compression or saturation depends on the repeater's design, gain, and dynamic range (maximum input and output power before the power amplifier reaches its P1 dB compression point depends on power amplifier selection). Beyond these levels, the P1 dB compression point is reached, meaning the power amplifier starts distorting the signal and reducing amplification linearity. When the input power exceeds P1 dB, the power amplifier no longer provides linear amplification, causing signal distortion, degraded SINR, and reduced EVM performance. Severe overloading can cause intermodulation products, increasing out-of-band emissions and interfering with other bands, all undesirable phenomena for a transmitting radio terminal device on the network.

[0082] To preventthe RF repeater power amplifier compression or saturation when directly connecting radio terminal device (uplink channel path) one needs to ensure that the radio terminal device output power will never exceed the RF repeater power amplifier limitations as those are specified according to its design, gain, and dynamic range. Especially on indoor or rural / remote areas where the transmitted signal strength of the radio terminal device is maximum due to high pathloss, RF repeater input power limitations should alwaysbe considered. However, such RF repeater input power limitations should be accounted hand-in-hand with the RF repeater output powertransmissions (orthe radio terminal device transmission limitations) towards the serving radio base station.Radio Terminal Device Power Category or Class

[0083] When directly connecting a radio terminal device to an RF repeater (uplink channel path), we should ensure that the transmitted uplink signal power at the RF repeater output (after amplification) does not exceed the standardized maximum transmit power of the radio terminal device category or class (i.e. the transmit power defined by 3GPP standards for LTE technology or similar standards for other technologies). Herein below is a general overview of the maximum transmitting power levels a radio terminal device is allowed to transmit according to its category or class (LTE and 5G NR, FR1 and FR2). The power levels are typically specified in terms of dBm (decibels per milliwatt) or watts:LTE Maximum Transmit Power (Uplink) - 3GPP TS 36.101 Specifications (FR1 Sub-6GHz):• Class 1 : 33dBm (2W) - High-power UE (e.g., industrial, CPE)• Class 2: 26dBm (0.4W) - (e.g., FWA CPE, loT devices)• Class 3: 23dBm (0.2W) - (e.g., Smartphones, tablets (default for most LTE UE))• Class 4: 21 dBm (0.125W) - (e.g., loT, Cat-M1 / NB-loT, and M2M applications)• Class 5: 20dBm (0.1 W) - (e.g., Low-power loT (NB-loT devices))5G NR Maximum Transmit Power (Uplink) - 3GPP TS 38.101 -1 Specifications (FR1 Sub- 6GHz):• Class 1 : 33dBm (2W) - High-power UE (e.g., industrial, CPE)• Class 2: 26dBm (0.4W) - (e.g., FWA CPE, loT devices)• Class 3: 23dBm (0.2W) - (e.g., Smartphones, tablets (default for most UE))• Class 4: 21 dBm (0.125W) - (e.g., loT, Cat-M1 / NB-loT, and M2M applications)• Class 5: 20dBm (0.1 W) - (e.g., NB-loT and MTC (Machine-Type Communication))Class 6: 14dBm (0.025W) - (e.g., Ultra-low-power UE (wearables, sensors))5G NR Maximum Transmit Power (Uplink) - 3GPP TS 38.101 -2 Specifications (FR2 mmWave):• Class 1 : 28dBm (0.63W) - High-power UE (e.g., FWA, CPEs, vehicular)• Class 2: 26dBm (0.4W) - (e.g., FWA CPE, enterprise devices)• Class 3: 23dBm (0.2W) - (e.g., Smartphones, tablets (default for most UE))• Class 4: 20dBm (0.1 W) - (e.g., loT, wearables, ARA / R devices)It's importantto note that these values are general guidelines, and the specific power levels may vary based on regional regulatory requirements, network configurations, and other factors. Additionally, these values represent uplink (transmission from the device to the network) maximum transmit power levels according to 3GPP and 3GPP NR technical specification documents. Accurate and detailed information is provided by standardization bodies such as 3GPP (for LTE) and 3GPP NR (for 5G) in their official technical specification documents or other for different technologies.Radio Terminal Device Uplink Power Control (UPC)

[0084] Uplink power control (UPC) is a crucial feature in wireless communication systems, specifically designed for controlling the transmission power of radio terminal devices when they communicate with the radio base station. The primary goal of uplink power control is to ensure that radio terminal devices transmit their signals at an appropriate power level, optimizing system performance while conserving their battery life and reducing radio base station interference. Radio terminal devices at the cell edge may need to transmit at higher power levels to maintain connectivity, while those closer to the radio base station reduce their power levels as such to reduce their uplink interference contribution. This helps in balancing the uplink load across different pathloss radio terminal device connections in the radio base station cell coverage area.

[0085] Several modern broadband technologies such as LTE and 5G employ adaptive power control mechanisms to adjust the transmission power of radio terminal devices dynamically. Their transmitted power level is not fixed but rather continuously adapted based on the channel conditions they encounter within a specified dynamic range. Thisdynamic range (in decibels - dB) is defined by the difference between the maximum and minimum power levels that a radio terminal device can use for uplink transmission. In our exemplary LTE technology network, uplink power control dynamic range typically spans 70dB, from around -40dBm (the minimum power level at which the radio terminal device can transmit) up to the standardized maximum of its category or class.Prior Art Repeater Automatic Gain Control (AGC)

[0086] To tackle the power amplifier compression or saturation problems when directly connecting a radio terminal device, prior art repeaters use Automatic Gain Control (AGC) circuits. AGC in RF repeaters functions to maintain a consistent and optimal signal strength level within the system despite fluctuations in the incoming signal strength. AGC systems continuously monitor / measure the strength of the incoming RF signal at the input to the repeater. If the incoming signal RF power strength varies, the AGC circuitry adjusts the power amplifier gains (e.g. by using variable gain amplifiers) - as such not to exceed the maximum output RF power of the power amplifiers. If the signal is weak, the AGC increases the gain of the power amplifier circuitry, as such to amplify the signal output to the desired level. Conversely, if the signal is too strong, the AGC reduces the gain to prevent distortion or overloading of the power amplifiers. As such AGC manages to always maintain RF signal power at its outputs at a preset level. An example where the incoming signal RF power strength varies at the input of the repeater is in moving vehicles.

[0087] However, although the use of AGC seems to overcome the power amplifier compression and saturation problem, directly connecting an RF repeaterto a radio terminal device remains highly problematic.

[0088] The transmitted signals in the uplink channel path will lose the uplink power control feature when an AGC is used. Since the AGC manages to always maintain RF signal power at a preset level, the continuously adapted (based on the channel conditions) radio terminal device transmitted power will be firmly fixed by the AGC at a predefined maximum power strength atthe output of the RF repeater. We know that uplink power control dynamic range ensures that radio terminal devices can adapt their transmit power according to their proximity to the radio base station site (low or high pathloss) and the quality of the uplink radio link (low or high interference). As a rule of thumb, radio terminal devices of low pathloss and low uplink interference (usually the case of low traffic / load cells) use lowtransmit power levels, while those of high pathloss and high interference (usually the case of high traffic / load cells) use higher transmit power levels to maintain a reliable connection.

[0089] By directly connecting a radio terminal device to an RF repeater that operates with an AGC, irrespective of the radio terminal device pathloss and uplink interference, the uplink power control feature of the device will be virtually disabled, and any transmit power dynamic range will be lost. Disabling uplink power control is very problematic for the radio access network since such radio terminal devices in some cases become uplink "overshooters", at least for their serving radio base stations. This is particularly important especially on moving vehicles that continuously change their radio channel conditions (i.e. assume the radio base station uplink interference from a vehicle that is having very low RF pathloss but transmit at higher than required / set power).

[0090] To ensure that the connected "one-way" amplify and "two-way" forward RF repeater for direct connection to the radio terminal device RF repeater output power (REPEATERPout) does not exceed the standardized maximum transmit power of the radio terminal device category or class (MODEMPout), while maintaining its full functionality-such as its uplink power control capabilities along the radio terminal device uplink power control dynamic range (REPEATERPout= MODEM Pout) without overloading the RF repeater power amplifier input ( PAP1JB-INFUT) and output P1 dB compression point (PAPI CIB-OUTPUT) one needs to consider the following:• Apply Input Power Limiting Mechanisms: The RF repeater uplink channel path should be designed to handle without saturation or compression of its power amplifier (PAPI CJB) the output power level of the connected radio terminal device (MODEM Pout). Such output power levels are defined from the radio terminal device category or class. To achieve that, attenuators or power limiters (AUL) should be considered in-line to the RF repeater power amplifier of gain (GUL) and input circuitry insertion losses (AINPUT INSERTION LOSSES). Therefore, the relationship of the input power limiting mechanism that needs to be satisfied is the following: o MODEMPout- AUL - AINPUT INSERTION LOSSES < PAp-idB- INPUT o MODEM Pout - AUL - AINPUT INSERTION LOSSES + G UL < P Apt dB - OUTPUT• Implement Proper Uplink Channel Path Output Power: The RF repeater must be designed with an amplifier gain (GUL) on the uplink channel path as such tocompensate all uplink channel path circuitry insertion losses, including any insertion losses introduced by the input (AINPUT INSERTION LOSSES), output (AOUTPUT INSERTION LOSSES) and the input power limiting mechanism (AUL), such that to maintain at its output (REPEATERpout) the exact power levels of the radio terminal device power levels (MODEMpout) at all times during uplink power control operation (REPEATERpout =o MODEMpout + GUL - AUL - AINPUT INSERTION LOSSES - AOUTPUT INSERTION LOSSES = REPEATERpoutwhere for REPEATERpout = MODEMpout, o GUL - AUL - AINPUT INSERTION LOSSES - AOUTPUT INSERTION LOSSES = 0 NET ZERO GAIN

[0091] As a rule of thumb, the RE repeater uplink channel path should be designed with the use of a power amplifier such that its output P1 dB compression point is always higher than the radio terminal device maximum output signal power including any insertion losses introduced at its output (PAPidB-ouTPUT > MODEMPout + AOUTPUT INSERTION LOSSES - specific power category or class radio terminal device) in order with appropriately selected circuitry insertion losses, input power limiting mechanisms and power amplifier gains to achieve net- zero uplink channel path (REPEATERpout = MODEMpout) as such to implement a repeater for direct connection to a specific radio terminal device power category or class. By applying these measures, the RE repeater uplink channel path can function efficiently, supporting stable communication while preserving the intended uplink power control dynamics of the radio terminal device without causing overload, compression, or industrial and regulatory violations.

[0092] It will be understood that the present invention uses a repeater for direct connection to the radio terminal device in order to achieve optimum radio terminal device connectivity of high network speeds and data throughput rates by:• fully utilizing MIMO and carrier aggregation technologies without encountering antenna isolation or de-coupling problems,Boost downlink signal strength while maintaining the uplink power levels to the radio terminal device power category or class without disabling the uplink power control feature of the radio terminal device in use, while at the same time,• safeguarding the RF repeater's circuitry (in the uplink channel path) and the radio terminal device circuitry (in the downlink channel path) from signal distortion caused by high power inputs.

[0093] By amplifying the downlink channel path one may improve the radio terminal device downlink connectivity to achieve from the serving network higher download speeds and data throughput rates capable of supporting an optimized modulation and coding scheme (MCS) of the technology and frequency they operate especially on high pathloss scenarios such as indoor or remote / rural environments.

[0094] On a different configuration, i.e. on a radio base station, by ensuring net-zero gain at the downlink channel path, while amplifying the uplink channel path, one may improve the radio terminal device connectivity on the uplink channel path and achieve from the serving network higher upload speeds and data throughput rates capable of supporting an optimized modulation and coding scheme (MCS) of the technology they operate.Radio Base Station Power Category or Class

[0095] When directly connecting a radio base station to an RF repeater (downlink channel path), we should ensure that the transmitted downlink signal power at the RF repeater output (after amplification) does not exceed the standardized maximum transmit power of the radio base station category or class (i.e. the transmit power defined by 3GPP standards for LTE technology or similar standards for other technologies). Herein below is a general overview of the maximum transmitting power levels a radio base station is allowed to transmit according to its category or class (LTE and 5G NR, FR1 and FR2). The power levels are typically specified in terms of dBm (decibels per milliwatt) or watts:LTE and 5G NR Maximum Transmit Power Levels (Downlink) - TS 38.104 for 5G NR and TS 36.104 for LTE in FR1 (sub-6GHz):• Class 1 : >46 dBm (40W+) per antenna port - Macro Base Station• Class 2: < 46 dBm (10-40W) - Micro Base Station• Class 3: < 30 dBm (1 W) - Pico Base Station• Class 4: < 24 dBm (0.25W) - Femto Base Station5G NR Maximum Transmit Power Levels (Downlink) - TS 38.104 for 5G NR in FR2 (mmWave):Class 1 : 36 dBm (4W), >80-85 dBm EIRP (Massive MIMO), Macro-Cell• Class 2: 30 dBm (1 W), 70-75 dBm EIRP Small-Cell• Class 3: 26 dBm (0.4W), 65-70 dBm EIRP Indoor Small-Cell, Micro-Cell• Class 4: 24 dBm (0.25W), 60-65 dBm EIRP Pico / Femto-Cell (low-power indoor use)It's important to note that these values are general guidelines, and the specific power levels may vary based on regional regulatory requirements, network configurations, and other factors. Additionally, these values represent downlink (transmission from the radio base station to the device - terminal or intermediate) maximum transmit power levels according to 3GPP and 3GPP NR technical specification documents. Accurate and detailed information is provided by standardization bodies such as 3GPP (for LTE) and 3GPP NR (for 5G) in their official technical specification documents or other for different technologies.

[0096] The repeater operates with net zero gain on the uplink channel path (i.e. the signal transmission from the radio terminal device to the radio base station direction). By net zero gain on the uplink channel path we mean that the uplinktransmitted signal has a zero signal power difference between the transmitting output port of the radio terminal device and the connected donor antenna.

[0097] Practically, the direct connect repeater should operate as "one-way" or single directional gain repeater, in order not to exceed the standardized maximum transmitted power of the radio terminal device, while maintaining the power control mechanism (uplink channel) of the radio terminal device in use.

[0098] It has to be noted at this point that in LTE (FDD) technology, according to the relevant 3GPP standards, the maximum allowable transmitted power of an LTE Category 3 radio terminal device is 23dBm or ~200mW(such limits forthe maximum transmitted power for the radio terminal device applies to any standardized wireless telecommunication technology irrespective on using power control or not).

[0099] Although the downlink and uplink channels, due to different gain on downlink and uplink channel paths are clearly unbalanced, in use, the radio terminal device uplink power control feature balances the links during the call initiation process.

[0100] We know that when a radio terminal device initiates a call or data session in our exemplary LTE network (or any other radio technologies that utilize uplink power control mechanisms), it goes through an initial access procedure. During this phase, the radio terminal device communicates with the serving radio base station to establish a connection. The radio terminal device sends a random access preamble to the radio base station. The radio base station responds by assigning a temporary identifier (RA-RNTI) to the radio terminal device and allocates resources for further communication. After this initial access, the radio base station continuously monitors the quality of the signal received from the radio terminal device.

[0101] The network (typically an LTE or 5G) is aware of the radio terminal device power class, which is transmitted as part of the UE's capabilities during the initial connection establishment. The power class indicates the maximum transmission power the UE is allowed to use. It helps the network determine the appropriate uplink power control settings.

[0102] When uplink power control is applied, the network uses the UE power class to set boundaries for power adjustments. It ensures that the UE does not exceed its maximum allowable transmit power while also maintaining reliable communication with the base station. The network controls uplink power to optimize coverage, minimize interference, and maintain link quality. The power class is typically defined as part of the UE's radio access technology (RAT) specifications, like LTE or 5G, and it plays a role in determining the maximum uplink power for the UE.

[0103] Based on this received signal quality, the radio base station sends power control commands (TPC - Transmit Power Control commands) to the radio terminal device. The TPC commands instruct the radio terminal device to adjust its uplink transmit power. If the received signal at the radio base station is weak, the TPC commands indicate the radio terminal device to increase its transmit power. Conversely, if the signal is strong enough, the TPC commands advise the radio terminal device to decrease its transmit power. ULPC operates on a continuous basis, with the radio terminal device adjusting its transmit power in response to the TPC commands received from the radio base station.

[0104] This uplink power control dynamic adjustment helps the repeater to operate with net zero gain on the uplink channel while maintaining both the downlink and uplink channelpaths balanced up to a pathloss that the radio link between the radio base station and the radio terminal device becomes uplink limited.

[0105] In one embodiment the radio terminal device I radio base station port is a radio terminal device port for direct, wired connection to a radio terminal device.

[0106] In one embodiment each direct connect RF repeater has net zero gain on the uplink channel path circuit.

[0107] In another embodiment, the uplink channel path may be used to upgrade or downgrade the class of the radio terminal device connected to the repeater. In one embodiment, a lower power class radio terminal device may be directly connected to the repeater, and the repeater used to upgrade its class from e.g. power class 2 to power class 1. This would require boosting uplink output power at the repeater output to a specific power level as such to upgrade its power class (positive gain). Upgrading radio terminal device power class is particularly important for deep indoor or deep rural scenarios where the radio terminal device to radio base station radio connection becomes uplink limited.

[0108] Conversely, in another embodiment, a higher power class radio terminal device may be directly connected to the repeater, and the repeater used to downgrade its class from e.g. power class 1 to power class 2. This would require reducing uplink output power at the repeater output (negative gain). To downgrade radio terminal device power class is particularly important for regulatory compliance purposes. It should be appreciated that when the repeater of the present invention is used with high gain directional antennas, compliance to ICNIRP, ETSI and FCC or other national regulations and standards concerning radio terminal device radiation emissions (EIRP) may be necessary.

[0109] To achieve upgrade or downgrade the class of the radio terminal device connected to the repeater (uplink channel path) the RF repeater must be designed as such to increase or decrease its output power (REPEATERPout) to the exact new power levels orthe new radio terminal device category or class. When upgrading the radio terminal device, REPEATERPout> MODEM Pout (for example when upgrading from Power Class 3 - 23dBm - to Power Class 1 - 33dBm -, the above relationship strictly becomes REPEATERPout= MODEMPout + 10dB) while when downgrading the radio terminal device, REPEATERPout < MODEMPout (for example when downgrading from Power Class 1 to Power Class 3, the above relationship strictly becomes REPEATERPout= MODEM Pout - 1 OdB). In these cases, the following uplink channel path repeater design guidelines should be considered:GUL - AUL - AINPUT INSERTION LOSSES - AOUTPUT INSERTION LOSSES — MODEM Pout + XdB POSITIVEGAIN• GUL - AUL - AINPUT INSERTION LOSSES - AOUTPUT INSERTION LOSSES — MODEM Pout - YdB NEGATIVE GAIN where X (upgrade) and Y (downgrade) may take discrete values that depend on the radio terminal device required power class upgrade or downgrade respectively.

[0110] On a different configuration, i.e. on a radio base station, the downlink channel path may be used to upgrade or downgrade the class of the radio base station connected to the repeater. In one embodiment, a lower power class radio base station may be directly connected to the repeater of the present invention, and the repeater used to upgrade its class from e.g. power class 4 (femto-RBS) to power class 3 (micro-RBS). This would require boosting downlink output power at the repeater output. To upgrade radio base station power class is particularly important for network radio planning and optimization design purposes.[01 1 1 ] Conversely, in another embodiment, a higher power class radio base station may be directly connected to the repeater, and the repeater used to downgrade its class from e.g. power class 2 to power class 4. This would require reducing downlink output power at the repeater output. To downgrade radio base station power class is particularly important for regulatory compliance purposes. It should be noted herein, that when the repeater of the present invention is used with high gain directional antennas, compliance to ICNIRP, ETSI and ECG or other national regulations and standards concerning radio base station radiation emissions (EIRP) may be necessary.

[0112] On an additional embodiment, i.e. on a Distributed Antenna System (DAS), one or more service antennas may be directly connected to the repeater, and the repeater used to eliminate DAS losses on both the downlink and the uplink channel paths for the specific service antenna(s). This would require matching the RBS or "off-air" repeater downlink channel output power as it was before the DAS input (i.e. at the RBS or "off-air" repeater connector) at the selected service antenna. Equally, the received uplink signals from the radio terminal devices serviced from the selected service antenna(s) should compensate for the DAS losses in the uplink channel path. In other words, the uplink and downlink channel paths should be set at equal gains, equal to the DAS losses.

[0113] The repeater system may comprise: a plurality of antenna ports; a plurality of radio terminal device ports; to support MIMO operation.

[0114] For example the system may comprise two antenna ports and two radio terminal device ports to support two data streams for MIMO operation. The system may comprise four antenna ports and four radio terminal device ports to support four data streams for MIMO operation. The system may comprise multi antenna ports and multi radio terminal device ports to support multi data streams for massive-MIMO operation.

[0115] In one embodiment the channel path with net zero gain comprises a power amplifier. The channel path with net zero gain may comprise an input power limiting mechanism in-line with the amplifier. The power limiting mechanism may be, for example, an attenuator.

[0116] In one embodiment a radio terminal device is connected to the at least one radio terminal device / RBS port, wherein the repeater circuit is configured such that the uplink (or downlink) signal power at the at least one antenna port is the same as the uplink (or downlink) signal power at the at least one radio terminal device / RBS port.[01 1 7] In an alternative embodiment a radio terminal device connected to the at least one radio terminal device / RBS port, wherein the plurality of repeater circuits is configured such that the uplink (or downlink) signal power at the at least one antenna port is more than the uplink (or downlink) signal power at the at least one radio terminal device / RBS port.

[0118] In an alternative embodiment a radio terminal device connected to the at least one radio terminal device / RBS port, wherein the plurality of repeater circuits is configured such that the uplink (or downlink) signal power at the at least one antenna port is less than the uplink (or downlink) signal power at the at least one radio terminal device / RBS port.

[0119] The invention also provides a self-contained repeater unit comprising: a repeater system according to the first aspect;a radio terminal device (RTD) connected to the at least one radio terminal device I radio base station (RBS) port; an antenna connected to the at least one antenna port.

[0120] The antenna may be a donor antenna (i.e. for wireless communication with a radio base station) in one embodiment. In another embodiment, the antenna may be a service antenna (i.e. for wireless communication with user equipment, such as in a distributed antenna system (DAS)).

[0121] The repeater system alone or the repeater system and a radio terminal device (RTD) may be contained in a housing attached to the antenna, thus forming an "active antenna" or an "active radio terminal device" respectively. The repeater system alone or the repeater system and the radio terminal device (RTD) may be contained in a housing attached to the antenna mounting plane. The self-contained repeater unit is preferably mountable on an elongate member for azimuth steering as a single unit.

[0122] The "active antenna" or "active radio terminal device" may comprise one or more omnidirectional antennas.

[0123] The "active antenna" or "active radio terminal device" may comprise one or more directional antennas.

[0124] The "active antenna" or "active radio terminal device" may comprise a plurality of antennas positioned at predetermined E-plane polarizations or X-multiple spacings.

[0125] The "active antenna" or "active radio terminal device" housing is preferably IP rated.

[0126] The radio terminal device may be customer premises equipment (CPE). The customer premises equipment (CPE) may be a modem, a modem / router or the radio terminal device may be an loT device. The active antenna system may have means to integrate a CPE, an loT device or other device employing a modem for connection to the network.

[0127] The invention also provides a distributed antenna system (DAS) comprising a repeater system according to the first aspect, a radio base station (RBS) or a prior art "off- air" repeater connected to the at least one radio terminal device / RBS port, and a service antenna connected to the at least one antenna port, wherein each repeater circuit has equalgains on both the uplink and downlink channel path between the RBS I "off-air" repeater and the service antenna. By equal gains herein we mean that the DAS pathlosses are compensated by the repeater on both downlink and uplink channel paths directly at the selected service antenna of the DAS.

[0128] The invention also provides a prior art "off-air" repeater assembly comprising a repeater system according to the first aspect, the "off-air" repeater connected to the at least one radio terminal device / RBS port and a donor antenna connected to the at least one antenna port, wherein each repeater circuit on the repeater system of the present invention has net zero gain on the uplink channel path between the "off-air" repeater and the donor antenna.

[0129] The invention also provides a repeater antenna system, comprising a scanning antenna system comprising one or more scanning antennas, wherein the one or more scanning antennas are configured to receive, for at least a first azimuth heading value and a second azimuth heading value, data comprising mobile communication signal and network parameters, a donor antenna system comprising one or more antennas, wherein the one or more antennas are configured to receive and transmit mobile communication signals, wherein the donor antenna system is connected to a repeater system according to the first aspect, and a controller connected to the scanning antenna system and a prior art "off-air" repeater system or other intermediate device, wherein the controller is configured to receive, process and compare the received mobile communication signals for the at least first azimuth heading value and the second azimuth heading value, determine whether the first azimuth heading value or the second azimuth heading value provides optimal network and signal parameters according to predefined criteria, and control connectivity of the prior art "off-air" repeater system or other intermediate device with the one or more donor antennas of the donor antenna system in accordance with the determination.

[0130] The invention provides a multi-directional antenna system for a hotspot, the system comprising a plurality of directional donor antennas, each antenna oriented in a different direction such that each antenna has a different dominant radio base station in use, at least one repeater system according to the first aspect, wherein each directional donor antenna is connected to the at least one prior art "off-air" repeater system or other intermediate device.

[0131] The invention provides a self-organizing directional antenna system, comprising a scanning antenna having a first horizontal beam width, the first antenna connected to a processor configured to establish communication between the scanning antenna and a radio base station (RBS), a radio terminal device (RTD), an RTD antenna system comprising at least one RTD antenna, the at least one RTD antenna having a second horizontal beam width, the second horizontal beam width being narrower than the first horizontal beam width, a repeater system according to the first aspect, the at least one RTD antenna connected to the at least one antenna port, and, a controller configured to, receive data identifying a RBS, determine the location of the RBS, using the location of the RTD antenna, and the position of the RBS, control the RTD antenna system to connect the RTD antenna to the RBS.Brief Description of Drawings

[0132] The present invention will now be described with reference to the following figures in which:FIGURES 1 a to 1 e are schematic views of prior art devices;FIGURES 2a to 2d are schematic views of a first repeater apparatus according to the present invention;FIGURE 3a is a schematic view of a second repeater apparatus according to the present invention;FIGURE 3b is a schematic view of a variation of the second repeater apparatus of Figure 3a;FIGURE 3c is a schematic view of a further variation of the second repeater apparatus of Figure 3a;FIGURE 4 is a schematic view of a third repeater apparatus according to the present invention;FIGURE 5a is a schematic view of a fourth repeater apparatus according to the present invention having dual data stream MIMO;FIGURE 5b is a schematic view of a variation of the fourth repeater with four data stream MIMO;FIGURE 6 is a schematic view of a sixth repeater apparatus according to the present invention;FIGURE 7 is a schematic view of a seventh repeater apparatus according to the present invention;FIGURES 8a & 8b is a view of a first active antenna / active RTD apparatus comprising a repeater according to the present invention;FIGURES 9a & 9b is a view of a second active antenna / active RTD apparatus comprising a repeater according to the present invention;FIGURE 10a is a schematic view of an eighth repeater apparatus in accordance with the invention;FIGURE 1 Ob is a schematic view of a variation of the eighth repeater apparatus;FIGURES 1 1 a & 1 1 b is a view of a third active antenna / active RTD apparatus comprising a repeater according to the present invention; and,FIGURES 12a & 12b is a view of a fourth active antenna / active RTD apparatus comprising a repeater according to the present invention.Description of the first embodiment

[0133] Referring to Figure 2a there is shown a first repeater 1000 according to the present invention. The repeater 1000 comprises a first port 1002 for connection to an external antenna 500 and a second port 1004 for connection to a radio terminal device 100.

[0134] The repeater 1000 comprises a housing 1006 in which the ports 1002, 1004 are connection points to the antenna 500 and radio terminal device 100 respectively. Within the repeater, the antenna port 1002 is connected to a first band selective duplex filter 1008, and the radio terminal device port 1004 is connected to a second band selective duplex filter 1010. Between the filters 1008, 1010 there is provided a downlink channel path 1012 and a separate uplink channel path 1014. The downlink channel path 1012 carries data in the downlink direction DL only, from the antenna 500 to the radio terminal device 100, and the uplink channel 1014 path carries data in the uplink direction UL only, from the radio terminal device 100 to the antenna 500. The filters 1008, 1010 act to filter the frequencybands for uplink and downlink channels (i.e. FDD). The radio base station 130 connects to the antenna 500 over the air, and via the repeater 1000 to the radio terminal device 100.

[0135] The downlink channel path has a low noise amplifier (LNA) 1016 with a gain G DL-

[0136] LNAs are used on the repeater of the present invention since the degradation of the radio terminal device noise figure upon direct connection to the RF repeater is undesirable. Repeaters of prior art use power amplifiers of high noise figures that if they were directly connected to a radio terminal device, they would drag the radio terminal device noise floor to higher levels as such they would degrade SINR and consequently the speed and throughput rates of the radio terminal device.

[0137] In the embodiment of Figure 2a the uplink channel path has a power amplifier 1018 with a gain Gur in series with an input power limiting mechanism (such as an attenuator) 1020 having an attenuation of AUL-

[0138] In some circumstances, amplifiers may be damaged and / or the signal could be degraded, by excessive power passing through them. Referring to Figures 2b to 2d, there is shown a protection apparatus 3000, being included in the repeater 1000 for protection of the amplifiers 1016, 1018 in Fig. 2a.

[0139] It will be understood that the features of Figures 2b to 2d are not shown in Figure 2a, but are nonetheless integrated therewith as will be apparent from the following description.

[0140] The amplifiers 1016, 1018 have a control input 3003 which = 1 for an active (powered) state, or 0 for inactive (unpowered) state.

[0141] The apparatus 3000 further comprises a coupler 3012, switches 3014, 3016, 3018 and a ground terminal 3020 via an attenuator 3022.

[0142] The coupler 3012 output (FWD) has a different coupling for the downlink (DL) and uplink (UL) signals- in other words the coupler has directivity. In some embodiments the coupling factor is smaller for the uplink than the downlink, which helps to balance the coupler output for the uplink and downlink channels since the uplink signals are much stronger than the downlink signals. In other embodiments the coupling factor is smaller for the downlink than the uplink, which help to balance the coupler output for the uplink and downlink channels since the downlink signals are much stronger than the uplink signals.

[0143] The coupler 3012 is on the donor antenna side of the amplifiers 1016, 1018 and is connected to the antenna 500 (or a port 1002 for connection thereof) on a first side, and the switch 3014 on a second side.

[0144] The first switch 3014 has a first connection to the coupler 3012, and can selectively connect the coupler 3012 to one of (i) the amplifiers (via the duplex filter 1008) and (ii) the second switch 3016, upon receipt of a control signal, in which the control signal = 1 for connection to the amplifiers 1016, 1018, and 0 for connection to the second switch 3016.

[0145] The second switch 3016 is connected to the first switch 3014 as described above, and can selectively connect to one of (i) the third switch 3018, or (ii) the attenuator 3022 and ground terminal 3020 upon receipt of a control signal, in which the control signal = 1 for connection to the ground terminal 3020, and 0 for connection to the third switch 3018.

[0146] The third switch 3018 has a first connection to the radio terminal device 100 (or the port 1004 for connection thereof) and can selectively connect the device 100 to one of the repeater LNAs 1016, 1018 and the second switch 3016 upon receipt of a control signal, in which the control signal = 1 for connection to the amplifiers, and 0 for connection to the second switch 3016.

[0147] The apparatus 3000 further comprises a controller 3024 shown in Figure 2d. The controller 3024 is connected to provide a control signal (1 or 0) via four channels to each of the repeater comprising the amplifiers 1016, 1018 and switches 3014, 3016, 3018.

[0148] The controller 3024 is configured to monitor the RSSI power at the input of the RF repeater of the present invention at all the downlink and uplink operating bands that the RF repeater 3002.

[0149] The controller 3026 comprises four input channels 3026. The controller 3026 is therefore capable of handling connection to four antennas (for example if a multiple antenna system is utilised). In this embodiment only a single antenna 500 is used, and as such only one channel is utilised, but it will be understood that the controller is suitable for multi-antenna operation if required. It will be understood that one or more antennas and therefore input channels 3026 can be used depending on the application.

[0150] A plurality of four switches 3028 are preselectors SPST (single pole single throw) switches. There is one switch per channel 3026. Only the switch of the active channel is closed while the switches of the inactive channels are open.

[0151] A further switch 3030 selects the active channel from the output of the switches 3028. The isolation of switch 3030 alone (active channel to inactive channels) is not enough to separate the channels adequately but is increased by the extra isolation from the switches 3028.

[0152] Downstream of the switch 3030, there is provided a band selection switch 3032 that selects the active band to be monitored, one of bands 1 , 3, 7, 28, 20, 8 in this example. The selected Band output from 3032 is connected to a plurality of band duplexers 3034 (one for each band to be selected) which comprises a filter pair that has a separate output for the band downlink and the band uplink.

[0153] A switch 3036 selects the active band downlink or uplink. It is a 12:1 switch (or 2n:1 where n is the number of bands).

[0154] The output from the switch 3036 goes to an amplifier 3038, which amplifies the signal to an appropriate level to be within the dynamic range of a detector 3040. The power detector 3040 is a true RMS linear-in-dB RF detector. It measures the RMS level (in dB) of the input signal, regardless of its modulation, which is essential for LTE signals that have a high crest factor. The output is proportional to the level (RSSI) of the input signal.

[0155] The output (VRMS) of the detector enters a uController 3042 and is converted to a (floating point) digital value through an ADC 3044 integrated in the uController 3042.

[0156] If the RSSI level is below a predetermined power value, a control signal 3046 is set to 1 which is outputto the switches 3012, 3016, 3018 and the RF repeater input 3003 to put the apparatus 3000 in normal mode (Fig. 2b).

[0157] If the RSSI level is above a predetermined power value, the control signal 3046 is set to 0 which is outputto the switches 3012, 3016, 3018 and the RF repeater input 3003 to put the apparatus 3000 in bypass mode (Figure 2c).

[0158] The purpose of switch 3016 is to provide an extra isolation added to the isolation of switches 3014 and 3018 so that the total gain of the loops created by the amplifiers and the bypass line is lower than zero (in dB) and the loops do not oscillate.

[0159] In Figure 2c, the bypass system of the present invention is at the bypass operating mode, the switches pass the signal to the bypass line, the amplifier power is off and the signal passes directly to the radio terminal device 100.

[0160] The mode of the bypass system is determined by a single control bit (CRL) 3046 coming from the controller 3024. The controller monitors all of the channels periodically and for each channel it monitors downlink and uplink of each RF band.

[0161] The apparatus 3000 is operated as follows:

[0162] The switches 3028, 3030, 3032, 3036 are set to select a specific channel, band downlink or uplink.

[0163] For the selected channel and band multiple measurements of the VRMS are taken for a defined observation time. The raw measurements (VRMS) are converted to the real signal level in dBm (at the antenna port) though a linear equation PdBm=CalA+ VRMS*CalB, where CalA and CalB are calibration factors stored in the controller memory through a calibration process. The calibration factors are different for each band, downlink or uplink.

[0164] The measurements are processed to get a reliable final value using a mean value algorithm. The table of measurements is sorted (using the quicksort algorithm) and we select as the final value the centre value of the sorted table. This method has the advantage of selecting the most probable value, excluding outliers (very low or very high values), which in the sorted table are near the beginning or the end of the table.

[0165] When all the bands (downlink and uplink) of a channel are scanned, the firmware compares the measured values to a predefined RF threshold (i.e. the radio terminal device 3010 P1 dB compression point). If in any band the level is found to be higher than the threshold, the system decides that the RF repeater will go to the bypass mode, otherwise it will be at the normal operating mode.

[0166] The process is repeated for all channels.

[0167] The RF repeater forward circuitry in the uplink channel path 1014, the amplifier 1018 and the input power limiting mechanism in the form of the attenuator 1020 are selected to achieve a "net-zero" gain circuitry on the uplink channel 1014. In other words, the attenuator value AUL and the amplifier gain GUL are selected to compensate for the system losses (i.e. the RF repeater circuitry insertion losses) and equate input RF power at the input of the repeater 1004 to output RF power at the output of the repeater 1002 (i.e. net zero gain). In this way the standardized maximum transmitted power of the selected radio terminaldevice is controlled, while the power control mechanism of the radio terminal device remains unaffected.

[0168] Advantageously, by using an input power limiting mechanism 1020 before the power amplifier 1018 in the uplink path one can control the input RE power to the power amplifier so as not to exceed the P1 dB compression point (PAP^B-INPUT). Assuming a power amplifier that its input P1 dB compression point is less than the radio terminal device transmitting power (including input amplifier circuitry insertion losses - AINPUT INSERTION LOSSES). it is easily understood that inserting a higher input signal power (MODEMPout- AINPUT INSERTION LOSSES) than the power amplifier's input P1 dB compression point (PApidB-iNPUT < MODEMpout - AINPUT INSERTION LOSSES), the power amplifier will compress. Attenuating the MODEMpousignal power by inserting an input power limiting mechanism such as an attenuator AUL, the power amplifier input circuitry could be controlled such that according to AUL values, PAPI CIB-INPUT > MODEM Pout - AINPUT INSERTION LOSSES - AUL, the input P1 dB compression point at the power amplifier to be satisfied. However, adding the power amplifier gain (assume a power amplifier of gain GUL), one also needs to control the output RE power of the power amplifier so as not to exceed its output P1 dB compression point. It is also understood that producing an output signal power (MODEMpout - AINPUT INSERTION LOSSES - AUL + GUL) higher than the power amplifier's output P1 dB compression point (PAPidB-ouTPUT < MODEMPout - AINPUT INSERTION LOSSES - AUL + G UL), the power amplifier will compress. Safeguarding the RE repeater s circuitry (in the uplink channel path) from signal distortion caused by high power inputs to the repeater circuit ofthe present invention one needs to design it according to the following conditions:• MODEM Pout>AUL>AlNPUT INSERTION LOSSES < P Apt dB - INPUT• MODEM Pout - AUL - AINPUT INSERTION LOSSES + G UL < P Apt dB - OUTPUT

[0169] The selection of the input power limiting mechanism AUL in the power amplifier input is critical to safeguard the RE repeater's circuitry (in the uplink channel path) from signal distortion caused by high power inputs from the radio terminal device. Using the input power limiting mechanism AUL in order to safeguard the RE repeater from compression or saturation - instead of an AGO circuitry, one achieves to maintain the uplink power control functionality intact. However, the selection of the input power limiting mechanism AUL should always be selected taking into account the total gains and losses on the RE repeater's circuitry at the uplink channel path.

[0170] The RF repeater must be designed with an amplifier gain (GUL) on the uplink channel path as such to compensate all uplink channel path circuitry insertion losses, including any insertion losses introduced by the input (AINPUT INSERTION LOSSES), output (AQUTPUT INSERTION LOSSES) and the input power limiting mechanism (AUL), such that to maintain at its output (REPEATERpout) the exact power levels of the radio terminal device power levels (MODEMpout) at all times during uplink power control operation (i.e. REPEATERpout = MODEM Pout). To achieve that, one needs to design the RF repeater of the present invention according to the following conditions:where for REPEATERPout= MODEMPout,• GUL - AUL - AINPUT INSERTION LOSSES - AQUTPUT INSERTION LOSSES = 0 NET ZERO GAIN

[0171] Please note that different radio terminal device classes lead to different input power limiting mechanism values, different power amplifier specifications lead to different input power limiting mechanism values, different system insertion losses lead to different input power limiting mechanism values. The invention therefore relates to a method of designing an RF repeater including the step of selecting an input power limiting mechanism that fulfils the requirements of both not exceeding the input and output P1 dB compression point of the RF repeater power amplifier (PAPidB.iNPUT, PAPI CIB-OUTPUT), and also maintaining the power output permitted by the class of radio terminal device directly connected to the repeater (REPEATERpout

[0172] In this way the maximum transmitted power for a selected radio terminal device, at the input and output of the power amplifier is controlled without the need of an automatic gain controller (AGC) or other means to maintain the quality of the re-transmitted signal without distortion due to power amplifier compression or saturation while at the same time the power control mechanism (uplink channel) of the radio terminal device is not compromised.

[0173] The net gain of the repeater 1000 in the uplink direction 1014 is zero. As such, for example, a signal transmission within a range of -40dBm to 23dBm (i.e. within the uplink power control dynamic range assuming an exemplary Category 3 device class maximum transmit power level) from the radio terminal device 100 into the repeater 1000 will exit the repeater 1000 at the same range i.e. -40dBm to 23dBm.

[0174] It will be noted that the RF repeater on the downlink channel path still provides positive gain on the radio terminal device allowing for improved downlink channel path connectivity achieving high network speeds and data throughput rates.First variation of the first embodiment

[0175] The first embodiment described above has "net zero" gain on the uplink channel path. This ensures that the power transmitted from the repeater to the RBS does not exceed the standardised maximum forthe class ofthe RTD. To upgrade the standardized maximum transmit power of the radio terminal device category or class, the first embodiment can be modified as it is described herein below.

[0176] The RF repeater must be designed with an amplifier gain (GUL) on the uplink channel path as such to compensate all uplink channel path circuitry insertion losses, including any insertion losses introduced by the input (AINPUT INSERTION LOSSES), output (AQUTPUT INSERTION LOSSES) and the input power limiting mechanism (AUL), such that to upgrade its output (REPEATERpout) to the exact power levels of the targeted radio terminal device power class (MODEM Pout) i. . REPEATERpout—MODEMpOut + XdB. Wherein XdB is the power class difference between the radio terminal device to be upgraded and the new radio terminal device power class required. To achieve that, one needs to design the RF repeater of the present invention according to the following conditions:• MODEM Pout - AUL - AINPUT INSERTION LOSSES < P Api dB - INPUT• MODEM Pout - AUL - AINPUT INSERTION LOSSES + G UL < P Apt dB - OUTPUT• MODEM Pout + G UL - AUL - AINPUT INSERTION LOSSES - AQUTPUT INSERTION LOSSES — REPEATERpout where for REPEATERpout = MODEMpout + XdB• GUL - AUL - AINPUT INSERTION LOSSES - AQUTPUT INSERTION LOSSES = XdB POSITIVE GAIN

[0177] Upgrading the class of RTD may be useful, for example, when higher uplink power transmission is beneficial such as in remote locations far from the RBS, when the radio terminal devices experience uplink power limitations.

[0178] It will be noted that the RF repeater on the downlink channel path still provides positive gain on the radio terminal device allowing for improved downlink channel path connectivity achieving high network speeds and data throughput rates.Second variation of the first embodiment

[0179] The first embodiment described above has "net zero" gain on the uplink channel path. This ensures that the power transmitted from the repeater to the RBS does not exceed the standardised maximum for the class of the RTD. To downgrade the standardized maximum transmit power of the radio terminal device category or class, the first embodiment can be modified as it is described herein below.

[0180] The RF repeater must be designed with an amplifier gain (GUL) on the uplink channel path as such to compensate all uplink channel path circuitry insertion losses, including any insertion losses introduced by the input (AINPUT INSERTION LOSSES), output (AQUTPUT INSERTION LOSSES) and the input power limiting mechanism (AUL), such that to downgrade its output (REPEATERpout) to the exact power levels of the targeted radio terminal device power class (MODEM Pout) i.e. RE P EZ\TE Rpout MI ^^D EMI poutYdB. Wherein YdB is the power class difference between the radio terminal device to be downgraded and the radio new radio terminal device power class required. To achieve that, one needs to design the RF repeater of the present invention according to the following conditions:• MODEM Pout - AUL - AINPUT INSERTION LOSSES < P Api dB - INPUT• MODEM Pout - AUL - AINPUT INSERTION LOSSES + G UL < P Apt dB - OUTPUT• MODEM Pout + G UL - AUL - AINPUT INSERTION LOSSES - AQUTPUT INSERTION LOSSES — REPEATERpout where for REPEATERpout = MODEMpout - YdB• GUL - AUL - AINPUT INSERTION LOSSES - AQUTPUT INSERTION LOSSES = YdB NEGATIVE GAIN

[0181] Downgrading the class of RTD may be useful, for example, when lower uplink power transmission is beneficial such as for compliance to ICNIRP, ETSI and FCC or other national regulations and standards concerning radio base station radiation emissions (EIRP) wherever may be necessary.

[0182] It will be noted that the RF repeater on the downlink channel path still provides positive gain on the radio terminal device allowing for improved downlink channel path connectivity achieving high network speeds and data throughput rates.Third variation of the first embodiment

[0183] According to a further variation, variable input power limiting mechanism may be provided in the uplink channel path. In reality, this may be achieved with a variable attenuator, or with the ability to switch between a plurality of attenuators or combinations of attenuators with different characteristics. Switching may be achieved by a physical switch (such as a DIP switch), or via an electronic controller on the device.Further variations of the first embodiment

[0184] First embodiment, and first, second and third variations thereof discuss having net zero, positive, negative and adjustable gain on the uplink channel path, and positive gain on the downlink channel path. It will be noted that it is within the scope of the present invention to have net zero, positive, negative and adjustable gain on the downlink channel path and positive gain on the uplink channel path.Description of the second embodiment

[0185] Referring to Figure 3a, the second embodiment is configured to operate with a single data stream (SISO configuration). This embodiment comprises a repeater 998 comprising three multiplexed band selective repeaters 10001, 10002, 10003. The band selective repeaters are each identical in configuration to the repeater 1000 from the first embodiment or any variations thereof (the repeaters of Figure 2a are shown by way of example).

[0186] In the second embodiment, each of the band selective repeaters 10001, 10002, 10003handles a separate frequency band. In this embodiment, band selective repeater 10001handles the LTE band B20, band selective repeater 10002handles the LTE band B8 and band selective repeater 10003handles the LTE band B28 (the bands in this embodiment are shown by way of example - different bands and / or different number of bands can be used).

[0187] The input and output signals to each band selective repeater are split into the separate channels using duplex filters 1008 and 1010. For this embodiment, the filters 1008, 1010 of each band selective repeater (denoted by the superscript numbers) are configured to filter downlink and uplink channels (the duplexer filters in this embodiment are shown by way of example - different filters such as duplexer, triplexer, quadplexer, hexaplexer or other multiplexer filters can be used).

[0188] The repeater 998 can therefore handle a multiband (in this example Band 8, 20, 28) single data stream (SISO configuration).

[0189] It will be understood that the bypass system of Figures 2b to 2d is integrated into the repeater 998.First variation of the second embodiment

[0190] Referring to Figure 3b, a repeater 6000 has a first, RBS port side RF circulator 6002, and a second, RTD port side RF circulator 6004. RF circulators are known in the art, and will not be described in detail here, suffice to say that downlink traffic only is fed from the antenna 500 to the downlink channel path 6012, and to the RTD 100, and uplink traffic only is fed from the RTD 100 to the uplink channel path 6014 and to the antenna 500.

[0191] As can be seen, there are three channel pass filters 6016 in the downlink channel path that feed amplifiers 6018, which in turn pass through filters 6020. There are three purposes for the existence of the filters:1. They restrict the signals passing to the amplifiers 6018 only within the corresponding bands, signals out of band are rejected and not amplified and do not enter the radio terminal device;2. They reject the uplink signal that passes in the inverse direction through the input circulator (such signals are attenuated by the isolation ofthe circulator, but can still be strong enough to get through), because its frequency is outside the bands of the filters.3. The uplink and downlink path amplifiers along with the circulators make a loop. It is ensured that the gain of the loop is in all cases lower than zero to prevent oscillation. This is accomplished in the frequency range that the circulator operates, because of the high isolation of the circulators in this range.However, outside their operating frequency range the circulators have very low isolation and the loop may oscillate. The filters ensure that out of the circulator operating frequency range the gain is very low (due to the extra attenuation of the filters).

[0192] Therefore downlink boost is separated into three, independently boosted, frequency bands. The uplink channel path 6014 has a single attenuator 6022 and amplifier 6024. Advantageously, this repeater design may operate on a TDD system without knowing (or identifying) the RF switching times between uplink and downlink channel paths beforehand.

[0193] In the case of a TDD system the uplink and downlink frequency bands are the same. In this case we have only one filter pair at the downlink path, covering the full bandwidth of the TDD system. The leak of the uplink amplified signal to the downlink path through the input circulator (which is amplified by the downlink amplifier) is not important because during the uplink state of the TDD system, the receiver amplifiers for its downlink are disabled and during the downlink state of the TDD system, the uplink signal is disabled.Second variation of the second embodiment

[0194] Referring to Fig. 3c, additional circulators 6003, 6005 are provided in the downlink and uplink channel paths respectively, to increase isolation for high power applications and matching purposes. The isolators 6003, 6005 are each connected to 50Q termination.Description of the third embodiment

[0195] Figure 4 is a further modification of Figure 3, in which within a repeater 996 there are provided two multiplexed band selective repeaters 9981, 9982per the second embodiment (which in turn each comprise three band selective repeaters 1000 perthe first embodiment).

[0196] Downstream of the antenna connection port there is provided a first high / low pass filter 1022. Upstream of the radio terminal device connection port there is provided a second high / low pass filter 1024. The filters 1022, 1024 separates the bands laying at the mid frequency band region and the bands laying at the low frequency band region. The multiplexed band selective repeater 9981deals with the low frequency LTE bands B8, B20, B28 per Figure 3, and multiplexed band selective repeater 9982handles the mid frequency LTE bands B1 , B3, B7.

[0197] A further option may comprise a band bypass system in which we boost only the mid-band frequencies (B1 , B3, B7) while leaving low-band frequencies un-boosted or bypassed (B8, B20, B28). This approach, to boost the downlink channel path according to the first aspect on the mid band frequencies only, and leave the low band frequencies un-boosted or bypassed, can have some advantages such as balancing the link budget between the low and mid band frequencies directly on the radio terminal device. Such bands, although will encounter the repeater filters insertion losses (i.e. the first 1022 and low 1024 high / low pass filter respectively), will be forwarded through the repeater's circuitry to the donor antenna (uplink channel) and the radio terminal device (downlink channel) respectively. In real-world deployments, radio terminal devices switch between low-band and mid-band frequencies depending on signal quality and availability (per network parameter setting specific). By keeping the link budgets similar for both bands, devices will experience smoother transitions between bands, as they won't have to contend with one band being received with higher signal strength compared to the other.

[0198] It will be noted that any frequency band could be used - the above frequency bands are licenced LTE bands widely used in Europe. In other territories such as Asia or the USA different LTE frequency bands are used. Othertechnologies such as 5G FR2 or IEEE 802.1 1 x may use different licensed or unlicenced frequency bands.

[0199] It will be understood that the band bypass system configuration may be applied to any frequency band within the LTE and 5G sub-6Hz and mmWave frequencies.

[0200] It will be noted that although the repeater 996 there are provided two multiplexed band selective repeaters 9981, 9982per the second embodiment, alternatively the repeaters 9981, 9982may each be replaced by a repeater 6000 of the first or second variation of the second embodiment (utilising circulators rather than filters).Description of the fourth embodiment

[0201] Referring to Figure 5a, a further development of the embodiment of Figure 4 is shown, adapted for dual data stream MIMO. The combined repeater is labelled 994.

[0202] A first RF repeater 9961with bands B1 , B3, B7, B8, B20, B28 and a second RF repeater 9962with bands B1 , B3, B7, B8, B20, B28 are positioned in parallel to form dual data stream MIMO. It will be noted that there are two antenna ports for connection to two antennas 5001, 5002. There are also two ports for direct connection to the radio terminal device 100.

[0203] It will be understood that the optional band bypass system of the third embodiment for the upper sub-6GHz bands (i.e. N77, N78 and others) may be integrated into the combined repeater 994.

[0204] It will be noted that any frequency band could be used - the above frequency bands are licenced LTE bands widely used in Europe. In other territories such as Asia or the USA different LTE frequency bands are used. Selected frequency bands could be boosted while leaving selected frequency bands unboosted or bypassed. Other technologies such as 5G or IEEE 802.1 1 x may use different licensed or unlicenced frequency bands.

[0205] It will be understood that the bypass system of Figures 2b to 2d is integrated into the combined repeater 994.

[0206] It will be noted that although the repeater 994 there are provided two repeaters 996, each with multiplexed band selective repeaters 9981, 9982per the second embodiment, alternatively the repeaters 9981, 9982may each be replaced by a repeater 6000 of the first or second variation of the second embodiment (utilising circulators rather than filters).Variation of the fourth embodiment

[0207] Referring to Figure 5b, a further development of the embodiment of Figure 5a is shown for a four datastream MIMO configuration, in which:• a first RF repeater 9961with bands B1 , B3, B7, B8, B20, B28;• a second RF repeater 9962with bands B1 , B3, B7, B8, B20, B28;• a third RF repeater 9963with bands B1 , B3, B7, B8, B20, B28; and,• a fourth RF repeater 9964with bands B1 , B3, B7, B8, B20, B28;

[0208] are positioned in parallel to form four data stream MIMO. The combined repeater is labelled 992.

[0209] It will be noted that any frequency band could be used - the above frequency bands are licenced LTE bands widely used in Europe. In other territories such as Asia or the USA different LTE frequency bands are used. Selected frequency bands could be boosted while leaving selected frequency bands unboosted or bypassed. Other technologies such as 5G or IEEE 802.1 1 x may use different licensed or unlicenced frequency bands.

[0210] All RF repeaters 996 in this embodiment are connected on the same radio terminal device but on different antenna ports. The antennas 500 are shown as separate devices butmay be part of the same antenna or under the same antenna housing. Multiple external antennas are required to be deployed at predetermined e-plane polarization or X-multiple spacing using identical cablings (i.e. length and type) in order that signal transmissions and receptions from each antenna are uncorrelated for MIMO to perform.

[0211] It will be understood that the bypass system of Figures 2b to 2d is integrated into the combined repeater 992.

[0212] It will be noted that although the repeater 994 there are provided four repeaters 996, each with multiplexed band selective repeaters 9981, 9982per the second embodiment, alternatively the repeaters 9981, 9982may each be replaced by a repeater 6000 of the first or second variation of the second embodiment (utilising circulators rather than filters).Description of the fifth embodiment

[0213] According to a fifth aspect of the present invention, the present invention may be utilised with the applicant's prior and co-pending applications as follows.

[0214] The repeater according to the present invention may be employed with the applicant's 3skelion™ system as described in WO 2016 / 087431 A1 , which is hereby incorporated herein by reference where permitted. In that application, a repeater system is provided in which at least one scanning antenna is configured to determine an optimum azimuth heading. A donor antenna is then configured to be directed to that heading to provide the optimal signal. In one embodiment the scanning and / or donor antennas may be moveable, and in another embodiment they may be a plurality of antennas connected to an RF switch.

[0215] It will be understood that the bypass system of Figures 2b to 2d is integrated into the combined repeater 992. In particular, channels 1 -4 describe a 4-sector bypass system, where 4 donor antennas may be supported by the system.

[0216] The repeater of the present invention can be connected to the donor antenna(s) to further improve the applicant's earlier system.

[0217] In another example, the present invention may be implemented with applicant's published patent application WO 2024 / 017902 A1 . In that application, a multi-directional antenna system is provided having a plurality of directional donor antennas, each of whichis oriented in a different direction to communication with different respective base stations. Each antenna is connected to a separate repeater and configured to serve a subset of users within a single hotspot.

[0218] The repeater of the present invention can be used with each of the donor antennas to improve such a system.

[0219] It will be understood that the bypass system of Figures 2b to 2d is integrated into the combined repeater 992. In particular, channels 1 -4 describe a 4-sector bypass system, where 4 donor antennas may be supported by the system.

[0220] In a still further example, the present invention may be implemented with applicant's published patent application WO 2024 / 246242 A1. In that application, the applicant discloses a self-organising directional antenna system that is automatically directed in the horizontal (azimuth) plane to establish communication with the radio base station (RBS) that provides the radio terminal device in use with optimum connectivity performance. The present invention may be combined with such a system to improve it.

[0221] It will be understood that the bypass system of Figures 2b to 2d is integrated into the combined repeater 992.Description of the sixth embodiment

[0222] Referring to Figure 6, a repeater 1000 according to the present invention (per the first embodiment) is directly connected to an "off-air" RF repeater 154 of the prior art as shown in Figure 1 d. In such configuration the repeater of the present invention is deployed as a pre-amplifier of the prior art "off-air" RF repeater 154. As shown in Figure 6, in this embodiment the repeater 1000 is provided external to the wall 158 with the "off-air" repeater 154 inside the wall 158.

[0223] Advantageously, the downlink gain of the repeater of the present invention may be deployed as a downlink channel pre-amplifier to the "off-air" prior art repeater in order to compensate the respective interconnection RF cable and other losses, thus offering increased signal to interference and noise ratio leading to upgraded MCS and eventually to higher downlink channel network speeds and throughput rates for the radio terminal devices serviced by the "off-air" prior art repeater.

[0224] It will be understood that the bypass system of Figures 2b to 2d is integrated into the combined repeater 992.Description of the seventh embodiment

[0225] In a further embodiment, the system is combined with a Time-Division Duplex (TDD) Radio Access Technology (RAT). Referring to Figure 7, a TDD (as opposed to Frequency Division Duplex - FDD RAT) embodiment is shown in which instead of filters, timed RF switches 1030, 1032 are provided. In 4G and 5G Time-Division Duplex (TDD) systems, the switching times between the uplink (UL) and downlin (DL) channels depend on the specific configuration and implementation of the network. Generally, in TDD, there's a special subframe configuration that defines the ratio of time allocated for uplink and downlink transmission. TDD systems use a frame structure where the transmission time is divided into subframes. Within each frame, there are specific subframes designated for uplink or downlink transmission. The switching between uplink and downlink for the RF switches 1030 and 1032 happens within these designated subframes.

[0226] In a 5G NR (New Radio) TDD, one of the common TDD configurations is the 1 millisecond (ms) subframe, which is further divided into DL and UL slots. The specific timing details can vary based on the subframe configuration, but as an example, the standard TDD subframe in 5G NR has the following structure:• Subframe duration: 1 ms• Number of slots per subframe: Typically 2 slots• DL-UL switch point: Usually, the switch point is in the middle of the subframe.

[0227] For example, in a TDD subframe with two slots, the switch point could be at 0.5 ms, meaning that the first half of the subframe is allocated to downlink transmission, and the second half is allocated to uplink transmission. However, it's essential to note that the exact configuration may vary depending on the specific TDD configuration and deployment, as such the RF switching times in the repeater of the present invention should be defined accordingly.

[0228] It will be understood that the bypass system of Figures 2b to 2d is integrated into the repeater 1000 of this embodiment.

[0229] It will be noted that instead of the switches 1030, 1032, the repeater 1000 of Figure 7 could use the circuitry of Figure 3b with appropriate band filtering, which as explained can handle TDD signals without the need for time dependent switching.Description of the eighth embodiment

[0230] Referring to Figures 8a and 8b there is shown a combined antenna, repeater and radio terminal device apparatus 2000 according to the present invention.

[0231] The apparatus 2000 comprises an antenna 500. The antenna is an LDPA (broadband) antenna having a radome 502, a backplane 504 and a plurality of four members 506 extending normal to the backplane 504, each member having a radiating element disposed thereon.

[0232] On a second side of the backplane 504, opposite to the radiating elements, there is provided a housing 2002 having a closure 2004. The housing 2002 is mounted on a pole member 2006.

[0233] Within the housing there is provided a repeater 992 according to the present invention (as described above). The repeater is configured for four data stream MIMO utilising the four antenna radiating elements. A radio terminal device in the form of a CPE, loT device or modem / router 2008 is provided, connected to the repeater 992. The CPE, loT device or modem / router 2008 is positioned within the housing 2002 connected to the antenna.Description of the ninth embodiment

[0234] The ninth embodiment (Figures 9a and 9b) is similar to the eighth, and has the same reference numerals. The antenna 500 is broadband (covers all sub-6GHz band) on 4 data stream MIMO configuration. The antenna of Figures 9a and 9b is a metal Vivaldi-Horn type antenna, which although more expensive than the PCB antenna of Figures 8a and 8b is more efficient.

[0235] In both the eight and ninth embodiments, it will be observed that the four data stream MIMO antenna deployment, the repeater and radio terminal device can be rotated as a single unit about a vertical (azimuth) steering axis if desired. Since RF repeaters boost the radio signal received at their input, depending on where the antenna is directed, thesignal strength level of the re-transmitted radio base station is fully dependent on the four data stream MIMO antenna accurate alignment.

[0236] The system of the eight and ninth embodiments is an "active antenna" or "active radio terminal device", IP rated unit, and can be easily installed external to a property or vehicle (it is expected that IP44 would be the minimum standard, although ideally this should be higher, such as IP65). Only the connection of an e.g. coaxial cables to the radio terminal device, or an ethernet cable to an internal access point or similar is required depending on the configuration. Therefore, assuming the installation complexity of multiple antennas positioned at predetermined E-plane polarizations or X-multiple spacings in order that signal transmissions and receptions of each to be uncorrelated for MIMO to optimally perform there are significant advantages with respect to ease, accurate and precise installation and alignment compared to the prior art.Description of the tenth embodiment

[0237] Referring to Figure 10a, a modified system comparable to the prior art system of Figure 1 e is shown. In this modified system, a direct connect repeater 1000 is provided between the splitter 164N and service antenna 166N according to the present invention.

[0238] The repeater 1000 is configured to provide equal gain on both the downlink and uplink channel paths. The gain in this example is assumed forthe compensation of the total RF power attenuation introduced by the Distributed Antenna System (DAS). This configuration overcomes both the downlink and uplink channel losses resulting from the multiple splitter losses and the long coaxial cable runs of the DAS which may be in the region of 10-20dB.First variation of the tenth embodiment

[0239] Referring to Figure 10b, there is shown a system in which the direct connect repeater of the present invention is connected between the directly connected RBS 130' and service antenna 166 for wireless connection to the RTD. There are no splitters in this variation- and the repeater 1000 may be configured to compensate for the feeder and other losses on both downlink and uplink channels.Second variation of the tenth embodiment

[0240] According to a further variation, variable input power limiting mechanism may be provided in either uplink channel path of the tenth embodiment, or first variation thereof. In reality, this may be achieved with a variable attenuator, or with the ability to switch between a plurality of attenuators or combinations of attenuators with different characteristics. Switching may be achieved by a physical switch (such as a DIP switch), or via an electronic controller on the device.

[0241] This is useful when it is desirable to achieve a specific gain on a channel (or channels), but the path loss may vary depending on installation, or equipment type. The installer can then select the attenuation to provide the required amount of gain to compensate e.g. feeder or other losse.Description of the eleventh embodiment

[0242] Referring to Figures 1 1 a and 1 1 b there is shown a combined antenna, repeater and radio terminal device apparatus (active antenna) 4000 according to the present invention.

[0243] The apparatus 4000 comprises four directional antennas 5001to 5004per the embodiment of Figure 5b. Each antenna has a radome 4004. There is a common backplane 4006.

[0244] On a second side of the backplane 4006, opposite to the radiating elements, there is provided a housing 4008 having a closure 4010. The housing 4010 is mounted for azimuth steering (not shown).

[0245] Within the housing 4008 there are provided the repeaters 9961to 9964of the embodiment of Figure 5b. A radio terminal device 100 in the form of a CPE, loT device or modem / router is provided, connected to the repeaters. The CPE, loT device or modem / router 100 is positioned within the housing 4008 connected to the antenna.

[0246] In the eleventh embodiment, it will be observed that the four data stream MIMO antenna deployment, the repeater and radio terminal device can be rotated as a single unit about a vertical (azimuth) steering axis if desired. Since RF repeaters boost the radio signal received at their input, depending on where the antenna is directed, the signal strength level of the re-transmitted radio base station is fully dependent on the four data stream MIMO antenna accurate alignment.

[0247] The system of the eleventh embodiment is a self contained, IP rated unit, and can be easily installed external to a property or vehicle (it is expected that IP44 would be the minimum standard, although ideally this should be higher, such as IP65). Only the connection of an e.g. ethernet cable to the radio terminal device to an internal access point or similar is required. Therefore, assuming the installation complexity of multiple antennas positioned at predetermined E-plane polarizations or X-multiple spacings in order that signal transmissions and receptions of each to be uncorrelated for MIMO to optimally perform (including cabling) there are significant advantages with respect to ease, accurate and precise installation and alignment compared to the prior art.Description of the twelfth embodiment

[0248] Referring to Figures 12a and 12b there is shown a combined antenna, repeater and radio terminal device apparatus (active antenna) 5000 according to the present invention.

[0249] The apparatus 5000 comprises a plurality of MIMO omnidirectional antennas 5001to 5004per the embodiment of Figure 5b. The antennas have a common radome 5004 and backplane 5006.

[0250] On a second side of the backplane 5006, opposite to the radiating elements, there is provided a housing 5008 having a closure 5010.

[0251] Within the housing 5008 there are provided the repeaters 9961to 9964of the embodiment of Figure 5b. A radio terminal device 100 in the form of a CPE, loT device or modem / router is provided, connected to the repeaters. The CPE, loT device or modem / router 100 is positioned within the housing 5008 connected to the antenna.

[0252] The system of the twelfth embodiment is a self contained, IP rated unit, and can be easily installed external to a property or vehicle (it is expected that IP44 would be the minimum standard, although ideally this should be higher, such as IP65). Only the connection of an e.g. ethernet cable to the radio terminal device to an internal access point or similar is required. Therefore, assuming the installation complexity of multiple antennas positioned at predetermined E-plane polarizations or X-multiple spacings in order that signal transmissions and receptions of each to be uncorrelated for MIMO to optimally perform (including cabling) there are significant advantages with respect to ease, accurate and precise installation and alignment compared to the prior art.Variations

[0253] In the aforementioned embodiments, the repeater in the uplink channel path has net zero gain and the downlink channel path has positive gain. Respectively, the repeater may be configured to have net zero gain on the downlink channel and the uplink channel path has positive gain.

[0254] In the aforementioned embodiments, the repeater in the uplink channel path has negative gain and the downlink channel path has net zero gain. Respectively, the repeater may be configured to have negative gain on the downlink channel and the uplink channel path has net zero gain.

[0255] In the aforementioned embodiments, the repeater has positive gain in both the uplink and the downlink channel path.

[0256] In the aforementioned embodiments, the repeater has equal gain in both the uplink and the downlink channel path.

[0257] The above embodiments and variations thereof are specific examples, but the skilled person will understand that the features described therein may be combined in many ways to achieve the desired function, such variations being implicitly disclosed herein.

Claims

Claims1. A repeater system comprising: at least one antenna port; at least one RTD / RBS port for direct, wired connection to a radio terminal device (RTD) or radio base station (RBS); at least one band selective repeater circuit between the at least one antenna port and the at least one RTD / RBS port.

2. A repeater system according to claim 1 , wherein the at least one repeater circuit has, between the at least one antenna port and the at least one RTD / RBS port: a downlink gain on a downlink channel path; and, an uplink gain on an uplink channel path; wherein the uplink gain and the downlink gain are different.

3. A repeater system according to claim 2, wherein at least one of the uplink gain and downlink gain is net zero.

4. A repeater system according to claim 3, wherein one of the uplink gain and downlink gain is net zero, the other of the uplink gain and downlink gain is net positive.

5. A repeater system according to claim 2 or 3, wherein one of: the uplink gain is net positive so as to upgrade a power class of a connected RTD; or, the downlink gain is net positive so as to upgrade a power class of a connected RBS.

6. A repeater system according to claim 2 or 3, wherein one of: the uplink gain is net negative so as to downgrade a power class of a connected RTD; or, the downlink gain is net negative so as to downgrade a power class of a connected RBS.

7. A repeater system according to any of claims 2 to 6, wherein the at least one repeater circuit comprises a input power limiting mechanism connected in series to an amplifier.

8. A repeater system according to claim 7, wherein the amplifier has a P1 dB compression point, and the input power limiting mechanism has a negative gain configured to reduce the signal power into the amplifier below the P1 dB compression point.

9. A repeater system according to claim 7 or 8, wherein the input power limiting mechanism has a variable negative gain.

10. A repeater system according to claim 9, wherein the negative gain is user- selectable.1 1. A repeater system according to any preceding claim, comprising a bypass circuit comprising a controller configured to sense a power input to the repeater system, and if the power input exceeds a predetermined level, bypass one or more amplifiers of the repeater system.

12. A repeater system according to claim 1 1 , wherein the controller of the bypass circuit comprises a plurality of channel inputs configured to alternately sense a power input on the plurality of channels.

13. A repeater system according to claim 1 1 or 12, wherein the controller of the bypass circuit comprises a band selection sub-system configured to alternate through a plurality of frequency bands and alternately sense a power input on the plurality of frequency bands.

14. A repeater system according to any preceding claim, comprising a plurality of band selective repeater circuits, each configured to handle a plurality of different bands within a respective frequency range.

15. A repeater system according to claim 14, wherein each multi-band selective repeater circuits within a respective frequency range comprises a pair of frequency range filters either side of an upstream amplifier circuit and a downstream amplifier.

16. A repeater system according to claim 14, wherein at least one band within a respective frequency range is not amplified.

17. A repeater system according to any preceding claim, comprising a first and a second circulator configured to separate upstream and downstream channel signals, wherein: the first circulator is connected to the at least one antenna port each of the uplink and downlink channel paths of the at least one band selective repeater circuit; and,the second circulator is connected to the at least one RTD I RBS port and each of the uplink and downlink channel paths of the at least one band selective repeater circuit.

18. A repeater system according to claim 17, comprising: a further first circulator in the downlink channel path and connected to 50Q termination; a further second circulator in the uplink channel path and connected to 50Q termination.

19. A repeater system according to any preceding claim, comprising: a plurality of n antenna ports; a plurality of n RTD ports; to support n data streams for MIMO operation.

20. A repeater antenna system, comprising: a scanning antenna system comprising one or more scanning antennas, wherein the one or more scanning antennas are configured to receive, for at least a first azimuth heading value and a second azimuth heading value, data comprising mobile communication signal and network parameters, a donor antenna system comprising one or more antennas, wherein the one or more antennas are configured to receive and transmit mobile communication signals, wherein the donor antenna system is connected to a repeater system according to any of claims 1 to 18; a controller connected to the scanning antenna system and the repeater system, wherein the controller is configured to: receive, process and compare the received mobile communication signals for the at least first azimuth heading value and the second azimuth heading value; determine whether the first azimuth heading value or the second azimuth heading value provides optimal network and signal parameters according to predefined criteria; and control connectivity of the repeater system with the one or more donor antennas of the donor antenna system in accordance with the determination.21 . A multi-directional antenna system for a hotspot, the system comprising: a plurality of directional donor antennas, each antenna oriented in a different direction such that each antenna has a different dominant radio base station in use; at least one repeater system according to any of claims 1 to 1 9; wherein: each directional donor antenna is connected to the at least one repeater system.

22. A self-organizing directional antenna system, comprising: a scanning antenna having a first horizontal beam width, the first antenna connected to a processor configured to establish communication between the scanning antenna and a radio base station (RBS); a radio terminal station (RTS); an RTS antenna system comprising at least one RTS antenna, the at least one RTS antenna having a second horizontal beam width, the second horizontal beam width being narrower than the first horizontal beam width; a repeater system according to any of claims 1 to 1 9, the at least one RTS antenna connected to the at least one antenna port; and, a controller configured to: receive data identifying a RBS; determine the location of the RBS; using the location of the RTS antenna, and the position of the RBS, control the RTS antenna system to connect the RTS antenna to the RBS.

23. A repeater system according to any of claims 1 to 1 9, comprising: an antenna connected to the antenna port for connection to a radio base station; and, an off-air RF repeater connected to the RBS / RTD port.

24. A repeater system according to any of claims 1 to 1 9, comprising: a first timed RF switch;a second timed RF switch; the RF switches configured to switch a downlink channel and an uplink channel of the RF repeater for a time division duplex signal.

25. A repeater system according to any of claims 1 to 1 9, comprising: a distributed antenna system connected to the at least one RTD / RBS port.

26. A repeater system according to claim 25, wherein the band selective repeater circuit is configured to boost the downlink and / or the uplink signal power to compensate for the distributed antenna system insertion losses.

27. A repeater system according to claim 26, wherein the band selective repeater circuit is configured to provide net zero losses on the downlink and / or the uplink signal power to compensate for the distributed antenna system insertion losses.

28. An active antenna comprising: a repeater system according to any of claims 1 to 1 9 or 23 to 27; at least one antenna connected to the antenna port; wherein the repeater system is mounted to a housing attached to the at least one antenna.

29. An active radio terminal device comprising: a repeater system according to any of claims 1 to 1 9 or 23 to 27; at least one antenna connected to the antenna port; and, a radio terminal device wherein the repeater system and the radio terminal device are mounted to a housing attached to the at least one antenna.

30. An active antenna according to claim 28 or an active radio terminal device according to claim 29, wherein the at least one antenna is omnidirectional.31 . An active antenna according to claim 28 or an active radio terminal device according to claim 29, wherein the at least one antenna is directional.

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