Device, system and method for switching between narrowband network and broadband network

Abstract

An apparatus, system, and method for switching between a narrowband network and a broadband network are provided. A radio device determines the status of the broadband network and receives access criteria from a narrowband network site indicating that a subset of a plurality of radio devices is capable of registering with the narrowband network site to communicate on the narrowband network. In response to the status meeting one or more given conditions and receiving the access criteria, when the radio device is communicating on the broadband network, the radio device may continue to communicate on the broadband network; or when the radio device is communicating on the narrowband network or attempting to register with the narrowband network site, the radio device switches from communicating on the narrowband network or attempting to register with the narrowband network site to communicating on the broadband network.

Description

Background Art

[0001] Radio devices of first responders and the like can be configured to communicate on narrowband networks and broadband networks. However, when certain conditions occur on the network, switching between these networks can be problematic. Brief Description of the Drawings

[0002] The drawings, together with the following detailed description, are incorporated in and form a part of this specification, and are used to further illustrate embodiments including the concepts of the claimed invention, and to explain the various principles and advantages of these embodiments, where like reference numerals refer to the same or functionally similar elements throughout the different views.

[0003] Figure 1 is a system for switching between a narrowband network and a broadband network according to some examples.

[0004] Figure 2 is a device diagram showing the device structure of a radio device for switching between a narrowband network and a broadband network according to some examples.

[0005] Figure 3 is a flowchart of a method for switching between a narrowband network and a broadband network according to some examples.

[0006] Figure 4 Depicts according to some examples Figure 1 of a system that implements aspects of a method for switching between a narrowband network and a broadband network.

[0007] Skilled artisans will appreciate that the elements in the figures are illustrated for simplicity and clarity and are not necessarily drawn to scale. For example, the dimensions of some elements in the figures may be exaggerated relative to other elements to help improve understanding of the embodiments of the present invention.

[0008] Device and method components have been represented in the figures by conventional symbols where appropriate, showing only those specific details relevant to understanding the embodiments of the present invention, so as not to obscure the disclosure of details that are obvious to those of ordinary skill in the art having the benefit of the description herein. Detailed Description

[0009] Radio devices of first responders, etc. can be configured to communicate on both narrowband networks and broadband networks. However, when certain conditions occur on the network, switching between such networks can be problematic. Specifically, when there is certain type of congestion at one or more networks that may not be easily detectable at the radio device, for example, automatic roaming between narrowband networks and broadband networks can cause temporary interruption of communication. Therefore, an improved technical method, device, and system for switching between narrowband networks and broadband networks are needed.

[0010] Accordingly, provided herein is a device, system, and method for switching between narrowband networks and broadband networks. For example, a radio device of a first responder, etc. can be configured to communicate on a narrowband network (e.g., such as a digital mobile radio network, a land mobile radio network, etc.) and a broadband network (e.g., such as a cellular telephone network, an LTE (Long Term Evolution) network, a 5G network, and a WiFi network, etc.). The radio device can initially communicate on either the narrowband network or the broadband network. When communicating on the narrowband network, the radio device may need to change from a narrowband network site to a broadband network site to continue communication, or, when communicating on the broadband network, the radio device can switch to the narrowband network when available. Specifically, the narrowband network can generally be dedicated to the radio device of the first responder, while the broadband network can be used for any radio device, among other possibilities.

[0011] As provided herein, the radio device can determine that the broadband network has sufficient signal strength (e.g., higher than a given signal strength threshold, which can be based on RSRP (Reference Signal Received Power) for LTE and / or 5G networks and / or based on Received Signal Strength Indicator (RSSI) for WiFi networks, and / or the broadband network meets any other appropriate conditions, such as based on RSRQ (Reference Signal Received Quality), among other possibilities. The radio device can further receive from a narrowband network site of the narrowband network an access criterion indicating that a subset of a plurality of radio devices, including the radio device, is capable of registering with the narrowband network site to communicate on the narrowband network.

[0012] Such access criterion can be received in a variety of scenarios. For example, when the radio device is to switch from one narrowband network site to the narrowband network site from which it receives the access criterion (e.g., the radio device is initially communicating on the narrowband network), such access criterion can be received from the narrowband network site.

[0013] Alternatively, when the radio device is initially communicating on the broadband network, such access criterion can be received and it can be located in the coverage area of the narrowband network site that sends the access criterion.

[0014] In another example, a radio device may communicate at a narrowband network site, which may send an access criterion indicating that a subset of radio devices that have most recently attempted to register with the narrowband network site may register with the narrowband network site. In such an example, such radio devices may attempt to register with the narrowband network site after being powered on and / or when entering the coverage area of the narrowband network site. In such an example, a subset of radio devices may attempt to register with the narrowband network site within a short duration, which may cause and lead to congestion.

[0015] In a similar example, multiple radio devices may attempt to re-register with the narrowband network site, again causing the access criterion to be sent.

[0016] However, it is to be understood that the access criterion may be received at the provided radio device in any suitable scenario.

[0017] Furthermore, it is to be understood that when a subset of multiple radio devices indicated by the access criterion all attempt to register with the narrowband network site in response to receiving the access criterion, the access criterion generally indicates that congestion may occur at the narrowband network site that sent the access criterion. Thus, instead of communicating at the narrowband network site, the radio device provided herein is configured to: continue to communicate on the broadband network when the radio device has been communicating on the broadband network; and switch from communicating on the narrowband network to communicating on the broadband network when the radio device is currently communicating on the narrowband network or is communicating on the narrowband network by attempting to register with the narrowband network site.

[0018] One aspect of the present specification provides a method, including: determining, at a radio device, one or more conditions of a broadband network; receiving, at the radio device, from a narrowband network site of a narrowband network, an access criterion indicating that a subset of multiple radio devices is capable of registering with the narrowband network site to communicate on the narrowband network; and in response to the one or more conditions of the broadband network satisfying one or more given conditions and receiving the access criterion: continuing, at the radio device, to communicate on the broadband network when the radio device is communicating on the broadband network; or switching, at the radio device, from communicating on the narrowband network or attempting to register with the narrowband network site to communicating on the broadband network when the radio device is currently communicating on the narrowband network or is attempting to register with the narrowband network site.

[0019] Another aspect of the present specification provides a radio device, comprising: a communication unit configured to communicate via a narrowband network and a broadband network; and a controller configured to: determine one or more conditions of the broadband network; receive, via the communication unit, from a narrowband network site of the narrowband network, an access criterion indicating that a subset of a plurality of radio devices can register with the narrowband network site to communicate on the narrowband network; and in response to one or more conditions of the broadband network meeting one or more given conditions and receiving the access criterion: when the radio device is communicating on the broadband network, continue to communicate on the broadband network via the communication unit; and when the radio device is communicating on the narrowband network or attempting to register with the narrowband network site, switch from communicating on the narrowband network or attempting to register with the narrowband network site to communicating on the broadband network via the communication unit.

[0020] Each of the aspects mentioned above will be discussed in more detail below, starting first with an example system and device architecture of a system in which the embodiments can be practiced, and then describing the processing blocks of improved technical methods, devices, and systems for implementing switching between a narrowband network and a broadband network.

[0021] Example embodiments are described herein with reference to flowcharts and / or block diagrams of methods, apparatus (systems), and computer program products according to example embodiments. It will be understood that each block of the flowcharts and / or block diagrams, and combinations of blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general purpose computer, a special purpose computer, or other programmable data processing apparatus to produce a particular and unique machine such that the instructions executed by the processor of the computer or other programmable data processing apparatus create means for implementing the functions / acts specified in the flowchart and / or block diagram block or blocks. In some embodiments, the methods and processes set forth herein need not be executed in the exact order shown, and similarly, the various blocks may be executed in parallel rather than sequentially. Accordingly, the elements of the methods and processes are referred to herein as "blocks" rather than "steps".

[0022] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to operate in a particular manner, such that the instructions stored in the computer-readable memory produce a manufacture including instructions that implement the functions / acts specified in the flowchart and / or block diagram block or blocks.

[0023] Computer program instructions can also be loaded onto a computer or other programmable data processing apparatus, which can be local or off-site, or can be accessed via the cloud in any of a software as a service (SaaS), platform as a service (PaaS), or infrastructure as a service (IaaS) architecture such that a series of operational blocks are caused to be executed on the computer or other programmable apparatus to produce a computer-implemented process, such that the instructions executed on the computer or other programmable apparatus provide for implementing the functions / actions specified in the flowchart and / or block diagram blocks or portions thereof. It is contemplated that any aspect or portion of any embodiment discussed in this specification can be implemented or combined with any other aspect or portion of any other embodiment discussed in this specification.

[0024] Referring to the accompanying drawings, further advantages and features consistent with this disclosure will be set forth in the following detailed description.

[0025] Turning attention to Figure 1 , which depicts an example system 100 for switching between a narrowband network and a broadband network. The various components of system 100 communicate via any suitable combination of wired and / or wireless communication links, and the communication links between the components of system 100 are depicted in Figure 1 and throughout this specification as double-ended arrows between respective components; the communication links can include wireless and / or wired links and / or any suitable combination of wireless and / or wired communication networks, etc.

[0026] System 100 includes a radio device 102, a narrowband network 104, a broadband network 106, a narrowband network site 108, and a broadband network site 110. As depicted, system 100 further includes a plurality of other radio devices 112, a gateway 114 between networks 104, 106, and a call server 116 in communication with broadband network 106. Although not depicted, system 100 can further include a call server in communication with narrowband network 104.

[0027] Radio device 102 is generally configured to communicate via both networks 104, 106 and can include any suitable communication device, including but not limited to digital mobile radio (DMR), land mobile radio (LMR), two-way radio, etc.; and / or any suitable communication device configured to communicate via both networks 104, 106.

[0028] The other radio devices 112 can be similar or different from radio device 102. Specifically, the other radio devices 112 are configured to communicate via narrowband network 104 and can be configured to communicate via broadband network 106.

[0029] The narrowband network 104 may include one or more of a digital mobile radio network and a land mobile radio network, or any suitable narrowband network, including but not limited to Project 25 (P25) networks, Terrestrial Trunked Radio (TETRA) networks, etc. Thus, in some examples, the narrowband network 104 may be dedicated to the communication of radio devices of first responders (e.g., because P25 networks and TETRA networks typically may include narrowband networks dedicated to first responders).

[0030] Conversely, the broadband network 106 may include one or more of a cellular telephone network, an LTE (Long Term Evolution) network, a 5G network, a WiFi network, etc. Thus, in some examples, the broadband network 106 may be used for communication to any suitable communication device, including communication operated by the public.

[0031] In addition, it is to be understood that wireless communication with the narrowband network 104 may typically occur via the narrowband network site 108, which may include one or more antennas and a base station controller, etc. Thus, the narrowband network site 108 may facilitate wireless communication between the radio device 102 and the narrowband network 104, and may also facilitate wireless communication between other radio devices 112 and the narrowband network 104.

[0032] Similarly, it is to be understood that wireless communication with the broadband network 106 may typically occur via the broadband network site 110, which includes one or more antennas and a base station controller, etc. Thus, the broadband network site 110 may facilitate wireless communication between the radio device 102 and the broadband network 106, and may also facilitate wireless communication between other radio devices 112 and the broadband network 106 when the other radio devices 112 are configured to communicate via the broadband network 106.

[0033] Generally, the narrowband network 104 is understood to communicate via a set of frequencies that are narrower and / or smaller than those of the broadband network 106.

[0034] In one example of the narrowband network 104, a narrowband LMR wireless network may operate in a conventional or trunked configuration. In either configuration, multiple radio devices are divided into separate groups of radio devices. However, the narrowband network 104 may include any other suitable narrowband network, such as a so-called conventional narrowband network, in which each radio device in a group is assigned to a specific radio channel (frequency or frequency and time slot) to communicate in association with the group of that radio device. Thus, each group is served by one channel, and multiple groups may share the same single frequency or frequency and time slot (in which case, in some examples, a group identifier may be present in the group data to distinguish between the groups).

[0035] In another example of the narrowband network 104, in a trunked narrowband network, radio devices use a pool of traffic channels for an almost unlimited number of groups of radio devices (and may also be referred to herein as talkgroups). Thus, all groups are served by all channels. The operation of a trunked radio network takes advantage of the probability that not all groups will need traffic channels for communication at the same time. In one example, when a group member requests a call on a control or rest channel, the call controller assigns a separate traffic channel for the requested group call, and all group members move from the assigned control or rest channel to the assigned traffic channel for the group call, where all radio devices at the site are idle on the control or rest channel waiting for a new call notification. In another example, when a group member requests a call on a control or rest channel, the call controller can convert the control or rest channel on which the radio devices are idle into a traffic channel for the call and instruct all radio devices not participating in the new call to move to the newly assigned control or rest channel selected from the pool of available channels. With a given number of channels, a greater number of groups can be accommodated in a trunked narrowband radio network compared to a conventional narrowband radio network.

[0036] Accordingly, the narrowband network 104 and the narrowband network site 108 can be configured to communicate with the radio devices 102, 112 according to any one of these narrowband configurations or any other suitable configuration. Similarly, the radio devices 102, 112 can be configured to communicate via the push-to-talk (PTT) protocol via the narrowband network 104 and the narrowband network site 108 (and / or other narrowband network sites). Additionally, control of PTT communication can occur via a control channel, which can be dedicated to the radio devices 102, 112 or can be a shared control channel (e.g., when bandwidth is restricted in some areas and thus shared by different networks).

[0037] However, the radio device 102 and optionally one or more radio devices 112 can be configured for PTT communication via the broadband network 106 through the broadband network site 110. For example, Open Mobile Alliance (OMA) Push-to-Talk over Cellular (OMA-PoC) is an example of an infrastructure broadband wireless application that enables PTT and "instant-on" features for traditional half-duplex radio devices but uses radio devices operating over modern broadband telecommunication networks. Using OMA-PoC, wireless radio devices such as mobile phones and laptops are able to act as PTT half-duplex radio devices for sending and receiving. Other types of PTT models and Multimedia Call Models (MMCM) are also available.

[0038] Floor control in an OMA-PoC session is typically maintained by a PTT server that controls communication between two or more wireless radio devices. Such functionality can be embodied in system 100 by call server 116. When a user of one of radio devices 102, 112 (e.g., assuming other radio device 112 is configured to communicate via broadband network 106) presses the PTT button, a request for permission to speak in the OMA-PoC session is sent from the user's radio device to the PTT server using, for example, Real-Time Transport Protocol (RTP) messages. If no other user is currently speaking in the PoC session (e.g., speaking using their radio device), an acceptance message is sent back to the user's radio device and then the user can speak into the radio device's microphone. Using compression / decompression (codec) technology, the user's voice is digitized and sent to the PTT server using discrete audio data packets (e.g., forming a time-varying audio data stream therewith), such as according to RTP and Internet Protocol (IP). The PTT server then sends the audio data packets to the other users of the PoC session (e.g., to the other radio devices in a group of radio devices or talk group to which the user subscribes) using one or more of, for example, unicast, point-to-multipoint, or broadcast communication technologies.

[0039] In some cases, as depicted, broadband and narrowband networks can be interfaced via a middleware system that translates between narrowband PTT standard protocols (such as DMR, P25, etc.) and broadband PTT standard protocols or applications (such as OMA-PoC). Such an intermediate middleware can include a middleware server for performing the translation and can be located in the cloud, at a dedicated local location of a client desiring to use both technologies, or at a common carrier that supports one or both technologies. For example, and with respect to Figure 1 , such a middleware server can be located in gateway 114.

[0040] Narrowband network site 108 can typically be configured to broadcast an access standard 118 that indicates which of radio devices 102, 112 can register with narrowband network site 108 to communicate via narrowband network 104.

[0041] For example, many and / or all of radio devices 102, 112 can attempt to register with narrowband network site 108 within a given time period, which can overload network and / or processing resources at narrowband network site 108. Such attempts to register with narrowband network site 108 can occur when narrowband network site 108 is turned on, and / or goes down and comes back online, and / or when radio devices 102, 112 are simultaneously within the coverage area served by narrowband network site 108 via the environment.

[0042] In one particular example, radio device 102 may initially communicate with broadband network 106 via broadband network site 110 and attempt to register with narrowband network site 108, e.g., while and / or within a given time period that multiple other radio devices 112 attempt to register with narrowband network site 108.

[0043] In another example, radio device 102 may initially communicate with narrowband network 104 via another narrowband network site (not depicted) and attempt to switch communication from the other narrowband network site to the depicted narrowband network site 108, e.g., because radio device 102 is moving (e.g., being carried by a moving first responder, etc.). In this example, radio device 102 may attempt to register with narrowband network site 108, e.g., while and / or within a given time period that multiple other radio devices 112 attempt to register with narrowband network site 108.

[0044] In another example, radio device 102 may initially be powered on and may attempt to register with narrowband network site 108, e.g., while and / or within a given time period that multiple other radio devices 112 attempt to register with narrowband network site 108.

[0045] In another example, radio device 102 may have been communicating on narrowband network site 108 (e.g., radio device 102 has registered with narrowband network site 108), and multiple other radio devices 112 may attempt to register with narrowband network site 108, e.g., when multiple other radio devices 112 are powered on and / or enter the coverage area of narrowband network site 108. In some of these examples, narrowband network site 108 may request radio device 102 to re-register with narrowband network site 108.

[0046] In any case, in any of these examples, narrowband network site 108 may detect a congestion condition and send access criteria 118.

[0047] To indicate that radio device 102 may be attempting to register with one of the narrowband network sites 108, or may have communicated with one or the other of networks 104, 106, the wireless communication links between sites 108, 110 and radio device 102 are depicted as dashed lines. To indicate that radio device 112 may be attempting to register with narrowband network site 108, the wireless communication link between narrowband network site 108 and other radio device 112 is depicted as a dashed line. However, for ease of illustration, the wireless communication link is only from broadband network site 110 to radio device 102, rather than other radio device 112, to indicate that in the depicted example, other radio device 112 may attempt to register with narrowband network site 108 rather than broadband network site 110.

[0048] In addition, for ease of illustration, Figure 1 example control channel 120 is depicted as a dashed line on the communication link between narrowband network site 108 and radio devices 102, 112 indicating that control channel 120 may be present at any suitable time.

[0049] Regardless of the situation, narrowband network site 108 can attempt to restrict which radio devices 102, 112 can register at any given time through broadcast access criterion 118, which can indicate that a subset of the multiple radio devices 102, 112 can register with narrowband network site 108 to communicate on narrowband network 104, and the multiple radio devices 102, 112 include radio device 102. For example, access criterion 118 indicates that only radio devices 102, 112 with respective identifiers that meet a certain criterion can attempt to register, such as those radio devices 102, 112 with only even-numbered identifiers (e.g., as opposed to odd-numbered identifiers), etc. However, access criterion 118 can have any suitable format, and / or can have any suitable indication of the subset of radio devices 102, 112 that can register with narrowband network site 108. Examples of such identifiers can include, but are not limited to, DMR device identifiers, LMR device identifiers, talk group identifiers, etc., and can include any other suitable identifier.

[0050] In addition, in one example of the access criteria 118 specific to the DMR protocol, the access criteria 118 can include a mask value and a mask size (e.g., how many bits in the mask value have to be matched starting from the least significant bit), and any radio device 102, 112 with an associated identifier that matches the mask pattern can register with the narrowband network site 108. In such an example, the radio device identifier can be provided in hexadecimal value, binary value, etc. Similarly, the mask value can be provided in hexadecimal value, binary value, etc. In one specific example, using binary values, the mask value can include "0b 0000 0000 0000 0000 0000 0000" (e.g., binary value), and the mask size can include "2 bits", which indicates that radio devices 102, 112 with an associated identifier having the last 2 bits as "00" in the binary value can register with the narrowband network site 108; specifically, radio device identifiers with DMR device identifiers ending in 4, 8, 12, 16, etc. (e.g., in base 10) are understood to have the last two bits as 00 in the binary value.

[0051] Thus, in another specific example, the mask value can include "0b 0000 0000 0000 0000 0000 0001" (e.g., binary value), and the mask size can include "2 bits", which indicates that radio devices 102, 112 with an associated identifier having the last 2 bits as "01" in the binary value can register with the narrowband network site 108; specifically, radio device identifiers with DMR device identifiers ending in 1, 3, 5, 7, etc. (e.g., in base 10) are understood to have the last two bits as 01 in the binary value.

[0052] Thus, when the radio device 102 (e.g., its associated respective identifier) meets the access criteria 118, the access criteria 118 can generally invite the radio device 102 to register with the narrowband network site 108.

[0053] The transmitted access criterion 118 can generally indicate that congestion may occur at the narrowband network site 108 because many other radio devices 112 that meet the access criterion 118 may attempt to register with the narrowband network site 108. Specifically, due to the detected congestion or expected (e.g., forecasted and / or predicted) congestion, the narrowband network site 108 may be segmenting the radio devices 102, 112 that attempt to register or may already be registered at the narrowband network site 108. Thus, it is to be understood that the narrowband network site 108 can generally be enabled to detect congestion, and / or forecast and / or predict congestion, and accordingly send and / or broadcast the access criterion 118, which can include but is not limited to inviting all radio devices that have registered with the narrowband network site 108 to re-register. An example of a condition under which the access criterion 118 can be sent and / or broadcast is when the narrowband network site 108 determines that the number of radio devices attempting to register with the narrowband network site 108 within a given time period is higher than a threshold number (e.g., 50, 100, or 200 radio devices attempting to register within 10 seconds, 20 seconds, 30 seconds, and other possibilities). During this congestion period, the response of the narrowband network site 108 to the registration attempts of radio devices such as the radio device 102 may be delayed; in addition, when a radio device such as the radio device 102 has registered with the narrowband network site 108, the call request of the radio device to the narrowband network site 108 may not succeed due to a conflict on the uplink to the narrowband network site 108.

[0054] Thus, if the radio device 102 attempts to communicate on the narrowband network 104 via the narrowband network site 108, or has already communicated on the narrowband network 104 (e.g., when the radio device 102 meets the access criterion 118), a delay may occur during registration or re-registration with the narrowband network site 108, which may delay communication through the narrowband network 104.

[0055] Thus, in response to receiving the access criterion 118, when the radio device 102 has been communicating on the broadband network 106, the radio device 102 can reject the attempt to register with the narrowband network site 108, regardless of whether the radio device 102 meets the access criterion 118, and the radio device 102 can continue to communicate on the broadband network 106.

[0056] Similarly, in response to receiving access criterion 118, when radio device 102 is communicating on broadband network 106 or attempting to register with narrowband network site 108, regardless of whether radio device 102 meets access criterion 118, radio device 102 can switch from communicating on narrowband network 104 or attempting to register with narrowband network site 108 to communicating on broadband network 106, and radio device 102 can continue to communicate on broadband network 106.

[0057] However, radio device 102 continuing to communicate via broadband network 106 and / or switching to communicate via broadband network 106 can further occur in response to the conditions of broadband network 106, as determined by radio device 102, meeting a given condition.

[0058] For example, radio device 102 can generally be configured to determine one or more specific conditions of broadband network 106, such as signal strength, signal quality, and others that will be described in more detail below. However, generally speaking, one or more conditions of broadband network 106 and broadband network site 110, as determined by radio device 102, generally indicate whether radio device 102 can communicate via broadband network 106.

[0059] Thus, radio device 102 can determine whether one or more conditions of broadband network 106 meet certain given conditions that indicate radio device 102 is capable of communicating via broadband network 106, such as the determined signal strength of broadband network 106 being higher than a given signal strength threshold that has been pre-configured at radio device 102, and / or the determined signal quality of broadband network 106 being higher than a given signal quality threshold that has been pre-configured at radio device 102.

[0060] For example, a given signal strength threshold can be selected such that when the signal strength of broadband network 106 is higher than (or equal to) the given signal strength threshold, broadband network 106 may be suitable for communication by radio device 102, and when the signal strength of broadband network 106 is lower than the given signal strength threshold, broadband network 106 may not be suitable for communication by radio device 102. For an LTE network, etc., an example of a signal strength that can be determined is the reference signal received power (RSRP), and a given RSRP threshold can be provided. For a WiFi network, etc., an example of a signal strength that can be determined is the received signal strength indicator (RSSI), and a given RSSI threshold can be provided.

[0061] For example, a given signal quality threshold can be selected such that when the signal quality of the broadband network 106 is higher than (or equal to) the given signal quality threshold, the broadband network 106 may be suitable for communication of the radio device 102, and when the signal quality of the broadband network 106 is lower than the given signal quality threshold, the broadband network 106 may not be suitable for communication of the radio device 102. For an LTE network or the like, an example of the signal quality that can be determined is the reference signal received quality (RSRQ), and a given RSRQ threshold can be provided.

[0062] Therefore, the situation of the broadband network 106 determined by the radio device 102 may depend on the type of the broadband network 106.

[0063] In addition, although "suitable" and / or "suitable communication" are relative terms, it should be understood that various given thresholds can be based on the error rates measured in communications above and below the given thresholds, and / or the given thresholds can be determined heuristically.

[0064] Therefore, the radio device 102 can generally be configured to: in response to the situation of the broadband network 106 satisfying a given situation and further in response to receiving the access criterion 118, when the radio device 102 has communicated on the broadband network 106, continue to communicate on the broadband network 106; and when the radio device 102 is communicating on the narrowband network 104 or is attempting to register with the narrowband network site 108, switch from communicating on the narrowband network 104 or attempting to register with the narrowband network site 108 to communicating on the broadband network 106.

[0065] Further details of which network 104, 106 the radio device 102 determines to communicate through will be described in more detail below.

[0066] Next, attention will be turned to Figure 2 , which depicts a schematic block diagram of an example of the radio device 102.

[0067] As depicted, the radio device 102 includes: a communication unit 202 configured to communicate via the narrowband network 104 and the broadband network 106, a processing unit 204, a random access memory (RAM) 206, a wireless transceiver 208, one or more wireless input / output (I / O) interfaces 210, a combined modulator / demodulator 212, a read-only memory (ROM) 214, a common data and address bus 216, a controller 218, and a static memory 220 storing at least one application 222. The controller 218 is understood to be communicatively connected to other components of the radio device 102 via the common data and address bus 216. Hereafter, the at least one application 222 will be interchangeably referred to as the application 222.

[0068] In addition, although memories 206, 214 are depicted as having a specific structure and / or configuration (e.g., separate RAM 206 and ROM 214), the memory of radio device 102 can have any suitable structure and / or configuration.

[0069] Although not depicted, radio device 102 can include one or more of an input device, a display screen, etc.

[0070] As Figure 2 shown, radio device 102 includes a communication unit 202, which is communicatively coupled to the common data and address bus 216 of processing unit 204.

[0071] Processing unit 204 can include a code read-only memory (ROM) 214, which is coupled to the common data and address bus 216 for storing data for initializing system components. Processing unit 204 can further include a controller 218, which is coupled to random access memory 206 and static memory 220 via the common data and address bus 216.

[0072] Communication unit 202 can include one or more wired and / or wireless input / output (I / O) interfaces 210, which can be configured to communicate with other components of system 100. For example, communication unit 202 can include an appropriate number of wireless transceivers 208, which are used to communicate with other appropriate components of system 100 including network sites 108, 110. For example, transceiver 208 can include a narrowband transceiver for communicating with narrowband network site 108 and a broadband transceiver for communicating with broadband network site 110.

[0073] Accordingly, the transceiver 208 may be adapted to communicate with a communication link and / or communication network suitable for communicating with other components of the system 100 including the network sites 108, 110, and the narrowband network 104 and the broadband network 106. For example, the transceiver 208 may be adapted to communicate with the Internet, a Digital Mobile Radio (DMR) network, a Project 25 (P25) network, a Terrestrial Trunked Radio (TETRA) network, a Bluetooth network, a Wi-Fi network (e.g., operating in accordance with the IEEE 802.11 standard (e.g., 802.11a, 802.11b, 802.11g)), a Long-Term Evolution (LTE) network, and / or other types of Global System for Mobile Communications (GSM) and / or 3rd Generation Partnership Project (3GPP) networks, a 5G network (e.g., a network architecture compliant with, for example, the 3GPP TS 23 specification series and / or a New Radio (NR) air interface compliant with the 3GPP TS 38 specification series), a Worldwide Interoperability for Microwave Access (WiMAX) network operating in accordance with, for example, the IEEE802.16 standard, and / or one or more of another similar type of wireless network. Accordingly, the transceiver 208 may include, but is not limited to, a cellular phone transceiver, a DMR transceiver, a P25 transceiver, a TETRA transceiver, a 3GPP transceiver, an LTE transceiver, a GSM transceiver, a 5G transceiver, a Bluetooth transceiver, a Wi-Fi transceiver, a WiMAX transceiver, and / or another similar type of wireless transceiver configurable to communicate via a radio network.

[0074] The transceiver 208 may also be coupled to a combined modulator / demodulator 212.

[0075] However, the communication unit 202 may further include one or more transceivers that are wired transceivers, such as an Ethernet transceiver, a Universal Serial Bus (USB) transceiver, or a similar transceiver configurable to communicate via a twisted pair, coaxial cable, fiber optic link, or a similar physical connection to a wired network.

[0076] The controller 218 may include ports (e.g., hardware ports) for coupling to other suitable hardware components of the system 100.

[0077] The controller 218 may include one or more logic circuits, one or more processors, one or more microprocessors, one or more GPUs (graphics processing units), and / or the controller 218 may include one or more ASICs (application specific integrated circuits) and one or more FPGAs (field programmable gate arrays), and / or another electronic device. In some examples, the controller 218 and / or the radio device 102 are not general purpose controllers and / or general purpose devices, but rather are devices specifically configured to implement the functionality of switching between a narrowband network and a broadband network. For example, in some examples, the radio device 102 and / or the controller 218 specifically include a computer executable engine that is configured to implement the functionality for switching between a narrowband network and a broadband network.

[0078] The static memory 220 includes a non-transitory machine-readable medium that stores machine-readable instructions to implement one or more programs or applications. Example machine-readable media include non-volatile storage units (e.g., erasable electronically programmable read-only memory (“EEPROM”), flash memory) and / or volatile storage units (e.g., random access memory (“RAM”)). In Figure 2 an example, the programming instructions (e.g., machine-readable instructions) that implement the functionality of the radio device 102 described herein are persistently held at the memory 220 and used by the controller 218, which appropriately utilizes volatile memory during the execution of such programming instructions.

[0079] In addition, the memory 220 stores instructions corresponding to at least one application 222 that, when executed by the controller 218, enable the controller 218 to implement the functionality for switching between a narrowband network and a broadband network, including but not limited to Figure 3 the blocks of the method set forth in

[0080] As depicted, the memory 220 further stores an identifier 224 of the radio device 102 (e.g., “radio identifier”), which may include DMR and / or LMR radio identifiers, among others, although other suitable identifiers are within the scope of this specification, including but not limited to International Mobile Equipment Identity (IMEI) identifiers, International Mobile Subscriber Identity (IMSI), Media Access Control (MAC) address, telephone number, and / or any suitable identifier that can identify the radio device 102 to the narrowband network site 108, and which may be used to invite the radio device 102 to register with the narrowband network site 108. However, generally, IMEI identifiers, IMSI identifiers, MAC addresses, telephone numbers, etc. may be more commonly used to register with a broadband network site rather than a narrowband network site. In some of these examples, the identifier 224 may alternatively be stored on a subscriber identity module (SIM) card (not shown).

[0081] As depicted, the memory 220 may further store an approved network / site list 226 that includes one or more identifiers of one or more broadband networks and / or one or more broadband network sites with which the radio device 102 has been approved to communicate. For example, the list 226 may include identifiers of cellular networks (e.g., LTE networks), WiFi networks, etc., cellular network sites, and / or their WiFi sites on which the radio device 102 has been approved to communicate (e.g., by an entity associated with the radio device 102, such as a police force). In the example described herein, the approved network / site list 226 may identify the broadband network 106 and / or the broadband network site 110. In a particular example, the approved network / site list 226 may include, but is not limited to, LTE network identifiers and / or Public Land Mobile Network (PLMN) identifiers and / or WiFi network identifiers, etc.

[0082] As depicted, the memory 220 may further store a denied network / site list 228 that includes one or more identifiers of one or more broadband networks and / or one or more broadband network sites that have denied the radio device 102 to communicate therewith. For example, the list 228 may include identifiers of cellular networks (e.g., LTE networks), WiFi networks, etc., cellular network sites, and / or their WiFi sites on which the radio device 102 has been denied to communicate (e.g., by an entity associated with the radio device 102, such as a police force). In a particular example, the denied network / site list 228 may include, but is not limited to, LTE network identifiers and / or Public Land Mobile Network (PLMN) identifiers and / or WiFi network identifiers, etc.

[0083] In the illustrated example, when the controller 218 executes one or more applications 222, it enables the controller 218 to: determine one or more conditions of a broadband network; receive an access criterion from a narrowband network site of a narrowband network, the access criterion indicating that a subset of a plurality of radio devices can register with the narrowband network site to communicate on the narrowband network; and in response to the one or more conditions of the broadband network satisfying one or more given conditions and receiving the access criterion: continue to communicate on the broadband network when the radio device has been communicating on the broadband network; or, when the radio device is communicating on the narrowband network or attempting to register with a narrowband network site, switch the radio device from communicating on the narrowband network or attempting to register with a narrowband network site to communicating on the broadband network.

[0084] Although details of the other radio devices 112 are not depicted, the other radio devices 112 may also have components similar to those of the radio device 102, which are suitable for their respective functionality. However, one or more of the other radio devices 112 may have functionality similar to that of the radio device 102, as described herein. Although details of the gateway 114 and the call server 116 are not depicted, the gateway 114 and the call server 116 may have components similar to those of the radio device 102, which are suitable for their respective functionality and / or in server and / or cloud computing device format. For example, the gateway 114 may generally be suitable for transitioning between narrowband PTT protocols (such as P25) and broadband PTT standard protocols (such as OMA-PoC). When at least one radio device is communicating via the broadband network 106, the call server 116 may generally be suitable for maintaining floor control in an OMA-PoC session and / or otherwise controlling communication between two or more radio devices, such as two or more of the radio devices 102, 112.

[0085] Attention is now turned to Figure 3 , which depicts a flowchart representing a method 300 for switching between a narrowband network and a broadband network. Figure 3 The operations of the method 300 in Figure 3 correspond to machine-readable instructions executed by the radio device 102 and, in particular, instructions executed by the controller 218 of the radio device 102. In the illustrated example, Figure 3 the instructions represented by the blocks of Figure 3 are stored in the memory 220, for example, as an application 222.

[0086] Figure 3 The method 300 in Figure 3 need not be executed in the exact order shown and, similarly, the various blocks may be executed in parallel rather than sequentially. Accordingly, the elements of the method 300 are referred to herein as "blocks" rather than "steps". Figure 3 The method 300 of Figure 1 may also be implemented on a variant of the system 100 of

[0087] At block 302, the controller 218 and / or the radio device 102 determines one or more conditions of the broadband network 106.

[0088] In some examples, one or more conditions of the broadband network 106 can include one or more of the signal strength of the broadband network 106, the signal quality of the broadband network 106, the reference signal received power (RSRP) of the broadband network 106, the received signal strength indicator (RSSI) of the broadband network 106, the reference signal received quality (RSRQ) of the broadband network 106, and one or more of the identifiers of one or more of the broadband network 106 and the broadband network site 110.

[0089] Furthermore, it is to be understood that the determined conditions may depend on the type of the broadband network 106. For example, when the broadband network 106 includes an LTE network, one or more conditions of the broadband network 106 can include one or more of the following: the signal strength of the broadband network 106, the signal quality of the broadband network 106, the reference signal received power (RSRP) of the broadband network 106, the reference signal received quality (RSRQ) of the broadband network 106, and one or more of the identifiers of one or more of the broadband network 106 and the broadband network site 110. However, when the broadband network 106 includes a WiFi LTE network, one or more conditions of the broadband network 106 can include one or more of the following: the signal strength of the broadband network 106, the received signal strength indicator (RSSI) of the broadband network 106, and one or more of the identifiers of one or more of the broadband network 106 and the broadband network site 110.

[0090] Thus, it is to be understood that in some examples, the controller 218 and / or the radio device 102 are configured to measure the signal strength and / or the signal quality of the network, which can include but is not limited to the signal strength of any one of the networks 104, 106, such as the signal strength of the signals broadcast by the respective sites 108, 110. Furthermore, in some examples, the controller 218 and / or the radio device 102 can determine the respective identifiers of the networks 104, 106 and / or the sites 108, 110 via the respective identifiers broadcast by the sites 108, 110.

[0091] At block 304, the controller 218 and / or the radio device 102 receive (e.g., via the communication unit 202) an access criterion 118 from the narrowband network site 108 of the narrowband network 104, the access criterion 118 indicating that a subset 102, 112 of a plurality of radio devices is capable of registering with the narrowband network site 108 to communicate on the narrowband network 104, the subset including the radio device 102.

[0092] Access criteria 118 typically include an indication of identifiers of a subset of a plurality of radio devices 102, 112 that are capable of registering with a narrowband network site 108 to communicate over a narrowband network 104. The identifiers of the subset of the plurality of radio devices 102, 112 can be indicated in any suitable manner, which can include, but is not limited to, criteria that define a given aspect of the identifier, such as an even identifier or an odd identifier, or a given number of bits (e.g., mask length) of a given mask pattern (e.g., in DMR trunking), or any other suitable criteria. For DMR, when the given number of bits (e.g., mask length) of a given mask pattern is 0 (e.g., equivalent to no mask), the subset of the plurality of radio devices 102, 112 indicated by the access criteria 118 can include all of the plurality of radio devices 102, 112. Thus, the subset of the plurality of radio devices 102, 112 indicated by the access criteria 118 can include less than all of the plurality of radio devices 102, 112, or can include all of the plurality of radio devices 102, 112.

[0093] In addition, in some examples, the subset can include radio device 102, while in other examples, the subset can exclude radio device 102. For example, the identifier of radio device 102 can meet the access criteria 118, or the identifier of radio device 102 can fail to meet the access criteria 118. Returning to the mask example, the identifier of radio device 102 can end with "00" (in binary), and the access criteria 118 can include a given number of bits (e.g., mask size) of "2" for a mask pattern of "0b 0000 0000 0000 0000 0000 0000" (in binary), thereby including radio device 102; conversely, the identifier of radio device 102 can end with "00" (in binary), and the access criteria 118 can include a given number of bits (e.g., mask size) of "2" for a mask pattern of "0b 0000 0000 0000 0000 0000 0001" (in binary), thereby excluding radio device 102.

[0094] At block 306, the controller 218 and / or the radio device 102 determine whether one or more conditions of the broadband network 106 (e.g., as determined at block 302) meet one or more given conditions.

[0095] Specifically, the one or more given conditions can depend on which of the one or more conditions of the broadband network 106 were determined at block 302. For example, the one or more given conditions can include one or more of the following:

[0096] - The signal strength of the broadband network 106 is higher than the given signal strength threshold described herein.

[0097] - The signal quality of the broadband network 106 is higher than the given signal quality threshold described herein.

[0098] The RSRP of the broadband network 106 is higher than the given RSRP threshold described herein.

[0099] The RSSI of the broadband network 106 is higher than the given RSSI threshold described herein.

[0100] The RSRQ of the broadband network 106 is higher than the given RSRQ threshold described herein.

[0101] - The identifier of one or more of the broadband network 106 and the broadband network site 110 is on the approval list 226.

[0102] - The identifier of one or more of the broadband network 106 and the broadband network site 110 is not on the rejection list 228. In some examples, when the identifier of one or more of the broadband network 106 and the broadband network site 110 is not on the rejection list 228 and not on the approval list 226, the controller 218 and / or the radio device 102 may determine that one or more given conditions are met at block 306.

[0103] In response to one or more conditions of the broadband network 106 meeting one or more given conditions and receiving the access criterion 118 (e.g., a "yes" decision at block 306), at block 308, the controller 218 and / or the radio device 102 determines whether the radio device 102 has communicated on the broadband network 106, or whether the radio device 102 is communicating on the narrowband network 104, or whether it is attempting to register with the narrowband network site 108.

[0104] When the radio device 102 has communicated on the broadband network 106, at block 310, the controller 218 and / or the radio device 102 continues to communicate on the broadband network 106 (e.g., via the communication unit 202).

[0105] When the radio device 102 is communicating on the narrowband network 104 or is attempting to register with the narrowband network site 108, at block 312, the controller 218 and / or the radio device 102 switches from communicating on the narrowband network 104 or attempting to register with the narrowband network site 108 to communicating on the broadband network 106 (e.g., via the communication unit 202).

[0106] In some of these examples, at block 312, method 300 may further include the controller 218 and / or the radio device 102 switching from communicating on the narrowband network 104 to communicating on the broadband network 106 after a given dwell time during which the radio device 102 is communicating on the narrowband network 104; such a dwell time is understood to define the shortest time that the radio device spends on a network before switching to another network, to prevent the radio device from rapidly and continuously switching between networks, which could disrupt communication with other radio devices. Any suitable dwell time is within the scope of this specification, including but not limited to 10 seconds.

[0107] Returning to block 306, in response to one or more conditions of the broadband network 106 not meeting one or more given conditions (e.g., no given condition is met, and assuming that access criterion 118 has been received) (e.g., the "no" decision at block 306), at block 314, the controller 218 and / or the radio device 102 may continue to communicate with the narrowband network 104 or attempt to register with the narrowband network site 108, even when the radio device 102 has to attempt registration multiple times and / or wait for further access criteria, etc.

[0108] Method 300 may include other suitable features for switching between networks 104, 106.

[0109] For example, when the radio device 102 is communicating on the narrowband network 104 or attempting to register with the narrowband network site 108, e.g., due to the implementation of block 314, etc., and / or at any other given time, method 300 may further include, further in response to one or more conditions of the broadband network 106 meeting one or more given conditions (e.g., as described with reference to block 306) and one or more of the following, the controller 218 and / or the radio device 102 switching from communicating on the narrowband network 104 or attempting to register with the narrowband network site 108 to communicating on the broadband network 106, the following being:

[0110] - Being refused registration at the narrowband network site 108. In such an example, the message received at the radio device 102 from the narrowband network site 108 is understood to be different from the access criterion 118 (e.g., which may invite the radio device 102 to register); rather, such a message may explicitly refuse the radio device 102 to register.

[0111] - Determine that the narrowband network site 108 is busy. In such an example, a message received at the radio device 102 from the narrowband network site 108 is understood to be different from the access criteria 118 (e.g., it may invite the radio device 102 to register); rather, such a message may indicate that the narrowband network site 108 is busy. Specifically, the narrowband network site 108 being busy can be indicated by the absence of free and / or available traffic channel resources available via the narrowband network site 108.

[0112] – Determine that a call group membership failure has occurred on the narrowband network 104. In such an example, the radio device 102 may attempt to belong to a call group, including but not limited to the primary call group, and the failure of belonging may be indicated by one or more of the following: not receiving a response to the membership request sent by the radio device 102 from the narrowband network 104 (e.g., the narrowband network site 108); receiving a membership failure message and / or a rejection message from the narrowband network 104 (e.g., the narrowband network site 108), etc.

[0113] – Lose communication with the control channel 120 on the narrowband network 104. For example, due to a failure of the control channel 120 and / or the signal strength of the control channel 120 falling below certain signal strengths, the data and / or signals on the control channel 120 may stop and / or cannot be received at the radio device 102.

[0114] - Determine that the control channel 120 includes a shared control channel. In some examples, the radio device 102 may store data (e.g., at the application 222 and / or separate from the application 222) at the memory 220 indicating whether the control channel 120 is a dedicated control channel or a shared control channel, such that the determination that the control channel 120 includes a shared control channel includes retrieving such data from the memory 220. Alternatively, the data received on the control channel 120 at the radio device 102 may indicate that the control channel 120 is shared, enabling the radio device 102 to determine that the control channel 120 is shared. In either example, when the control channel 120 is shared, it is understood that the bandwidth and / or frequency of the control channel 120 may be shared with other communication networks.

[0115] - It is determined that there is no active connection on the narrowband network 104. For example, as depicted, there is a communication link between the narrowband network site 108 and the narrowband network 104, which can represent an active connection between the narrowband network site 108 and the narrowband network 104. In some examples, such an active connection may not exist and / or may disappear and / or fail (e.g., due to the narrowband network site 108 failing to maintain the connection, etc.). In such examples, the radio device 102 can determine that although there is communication with the narrowband network site 108, there is no communication with the narrowband network 104. In other words, in these examples, the narrowband network site 108 can be isolated from other narrowband network sites of the narrowband network 104. Additionally, in some examples, the narrowband network site 108 can broadcast (e.g., in a message) that an active connection is available, which is received by the radio device 102; when the radio device 102 fails to receive such a broadcast and / or message from the narrowband network site 108, the radio device 102 can determine that the active connection is not available via the narrowband network site 108.

[0116] However, assuming that one or more conditions of the broadband network 106 determined at block 302 satisfy one or more given conditions described with respect to block 306, the radio device 102 can switch from communicating on the narrowband network 104 or from attempting to register with the narrowband network station 108 to communicating on the broadband network 106 under any other suitable conditions.

[0117] In other examples, the method 300 can further include the controller 218 and / or the radio device 102: communicating on the broadband network 106; determining one or more respective conditions of the narrowband network 104; and in response to one or more respective conditions of the narrowband network 104 satisfying one or more respective given conditions, switching from communicating on the broadband network 106 to communicating on the narrowband network 104. These examples assume that the radio device 102 is communicating on the broadband network 106, e.g., due to the implementation of block 310 and / or block 312 and / or at any other suitable time.

[0118] Furthermore, one or more respective conditions of the narrowband network 104 determined by the radio device 102 can include one or more of the following: the signal strength of the narrowband network 104, and the identifier(s) of one or more of the narrowband network 104 and the narrowband network site 108, and one or more given conditions can respectively include one or more of the following: the signal strength of the narrowband network 104 is higher than a given signal strength threshold; the identifier(s) of one or more of the narrowband network 104 and the narrowband network site 108 is on the approved list 226; the identifier(s) of one or more of the narrowband network 104 and the narrowband network site 108 is not on the rejection list 228, etc.

[0119] However, in these examples, the switching of the controller 218 and / or the radio device 102 from communication on the broadband network 106 to communication on the narrowband network 104 can occur in response to one or more respective conditions of the narrowband network 104 meeting one or more respective given conditions and one or more of the following:

[0120] - Determining that the broadband network 106 has dropped offline. For example, the broadband network 106 can (e.g., temporarily) stop operating, and although a wireless communication link can be established between the radio device 102 and the broadband network site 110, access to the broadband network 106 cannot be provided, thereby indicating to the radio device 102 that the broadband network 106 has dropped offline.

[0121] - Determining that there is no active connection to the broadband network 106, similar to that described above regarding an active connection to the narrowband network 104.

[0122] - Determining that there is no connection to the Internet on the broadband network 106. For example, the broadband network 106 may be communicating with other broadband networks that form at least a part of the Internet, but such communication may fail. The radio device 102 can determine such a failure by attempting to communicate on the Internet via the broadband network 106 and failing. Specifically, the call server 116 can be connected to the broadband network 106 via the Internet; thus, in the absence of a connection to the Internet on the broadband network 106, the radio device 102 may not be able to communicate with the call server 116 to establish or receive calls and messages, etc.

[0123] – Losing the connection to the call server 116 on the broadband network 106, where the call server 116 is used to coordinate one or more calls and messages between the broadband network 106 and the narrowband network 104, as previously described. For example, the radio device 102 may have established a connection with the call server 116 (e.g., under the OMA-PoC broadband wireless application and / or standard), and this connection may be lost due to the call server 116 dropping offline, etc. In such an example, the radio device 102 can determine that the connection to the call server 116 is lost due to the call server 116 failing to respond to signaling messages from the radio device 102.

[0124] - Determining that the call server 116 is unavailable. For example, the radio device 102 can receive a message from the call server 116 indicating that the call server 116 is unavailable.

[0125] - Determine that the radio device 102 has been logged out from the call server 116. For example, in order to use the call server 116, the radio device 102 may need to log in to the call server 116 using pre-configured credentials. When the radio device 102 is not logged in, the radio device 102 can determine that the radio device 102 has been logged out from the call server 116. Alternatively, and / or additionally, the call server 116 can log out the radio device 102 from the call server 116 and send a corresponding message to the radio device 102.

[0126] - Determine that the gateway 114 between the broadband network 106 and the narrowband network 104 is unavailable. For example, the radio device 102 can receive a message indicating that the gateway 114 is unavailable from the gateway 114 (e.g., via the narrowband network 104 or the broadband network 106, and / or its sites 108, 110), and / or communication with the broadband network 106 via the gateway 114 may fail.

[0127] [In some specific examples, the method 300 can further include the controller 218 and / or the radio device 102: communicate on the broadband network 106; determine that the signal strength of the narrowband network 104 is higher than a given signal strength threshold; receive the access criteria 118 from the narrowband network site 108; and switch communication from the broadband network 106 to the narrowband network 104 when further access criteria are received from the narrowband network site 108, the further access criteria indicating that all radio devices 102, 112 can register on the narrowband network 104, rather than just the subset indicated by the access criteria 118. In other words, in these examples, the radio device 102 may have switched to communication on the broadband network 106 and may later switch to communication on the narrowband network 104 when the narrowband network site 108 broadcasts further access criteria, the further access criteria indicating that all and / or any radio devices 102, 112 (e.g., or any other radio device) can register to communicate on the narrowband network 104 via the narrowband network site 108. Such examples can further include: the controller 218 and / or the radio device 102 confirm that there is an active connection between the narrowband network site 108 and the narrowband network 104 before switching communication from the broadband network 106 to the narrowband network 104.

[0128] Next, attention will be turned to Figure 4 which depicts aspects of the method 300. Figure 4 Similar to Figure 1 where the same components have the same numbers.

[0129] As depicted, radio device 102 has made a determination 402 (e.g., at block 302 of method 300), where the signal strength (e.g., “SS”) of broadband network 106 (e.g., and / or broadband network site 110) is higher than a given signal strength threshold (e.g., “SS threshold”). For ease of illustration, determination 402 is depicted adjacent to radio device 102, however the dashed line extending from radio device 102 to determination 402 indicates that determination 402 is made at radio device 102. Alternatively, determination 402 can be based on signal quality, RSRP, RSSI, and / or RSRQ and their respective given thresholds.

[0130] As depicted, radio device 102 has further received an access criterion 118 that indicates that a subset of radio devices 102, 112, which includes radio device 102, is able to register with narrowband network site 108. However, radio device 102 refuses to register with narrowband network site 108 and instead communicates with broadband network 106, e.g., by establishing a communication link 404 with broadband network site 110. For example, Figure 4 compared with Figure 1 the communication link between radio device 102 and broadband network site 110 is depicted as a solid line, indicating that radio device 102 has continued to communicate with broadband network 106 (e.g., at block 310 of method 300), or has switched from communicating on narrowband network 104 to communicating on broadband network 106 (e.g., at block 310 of method 300). Specifically, Figure 4 compared with Figure 1 there may be at least temporarily no communication link between radio device 102 and narrowband network site 108, and / or until radio device 102 later determines whether to switch from communicating on broadband network 106 to communicating on narrowband network 104.

[0131] It should be apparent from this detailed description above that the operations and functions of the electronic computing devices described herein are complex enough that they are required to be implemented on a computer system and in fact cannot be performed in a human brain. Electronic computing devices such as those described herein are understood to require and provide speed, accuracy, and complexity management that are not achievable by human mental steps in addition to the inherent digital nature of such operations (e.g., the human brain cannot directly interface with RAM or other digital storage, cannot send or receive electronic messages, control call processing devices, etc.).

[0132] In the foregoing specification, specific embodiments have been described. However, those of ordinary skill in the art will appreciate that various modifications and changes can be made without departing from the scope of the invention set forth in the following claims. Accordingly, the specification and drawings are to be regarded as illustrative rather than restrictive, and all such modifications are intended to be included within the scope of this teaching. Benefits, advantages, solutions to problems, and any element that may cause any benefit, advantage, or solution to occur or become more pronounced should not be construed as a critical, required, or essential feature or element of any or all claims. The invention is defined only by the appended claims, which include any modifications made during the pendency of this application and all equivalents of those claims as issued.

[0133] In addition, in this document, relational terms such as first and second, top and bottom, etc. may be used only to distinguish one entity or action from another entity or action, without necessarily requiring or implying any actual such relationship or order between these entities or actions. The terms "comprise", "comprising", "have", "having", "include", "including", "contain", "containing" or any other variant thereof are intended to cover non-exclusive inclusion, such that a process, method, article or apparatus that comprises, has, includes, contains a list of elements does not include only those elements but may also include other elements not expressly listed or inherent to such process, method, article or apparatus. Elements proceeded by "comprise a", "have a", "include a", "contain a" do not, without more constraints, preclude the presence of additional identical elements in the process, method, article or apparatus that comprises, has, includes, contains that element. Unless expressly stated otherwise herein, the terms "a" and "an" are defined as one or more. The terms "substantially", "essentially", "approximate", "about" or any other version thereof are defined as being close to what is understood by a person of ordinary skill in the art, and in one non-limiting embodiment, the term is defined as within 10%, in another embodiment within 5%, in another embodiment within 1% and in another embodiment within 0.5%. Without more restrictive modifiers such as "only one of", and when applied herein to two or more subsequently defined options such as "one of A and B", the term "one of" shall be construed to mean any one of the options in the list standing alone (e.g., A alone or B alone) or any combination of two or more of the options in the list (e.g., A and B together). Similarly, without more restrictive modifiers such as "only one", when applied herein to two or more subsequently defined options such as "at least one of A or B" or "one or more of A or B", the terms "at least one" and "one or more" shall be construed to mean any one of the options in the list standing alone (e.g., A alone or B alone) or any combination of two or more of the options in the list being present (e.g., A and B together).

[0134] An apparatus or structure that is "configured" in a certain way is configured at least in that way, but may also be configured in ways not listed.

[0135] As used herein, the terms "coupled", "coupling", or "connected" can have several different meanings depending on the context in which they are used. For example, the terms "coupled", "coupling", or "connected" can have a mechanical or electrical meaning. For example, as used herein, the terms "coupled", "coupling", or "connected" can indicate that two elements or devices are directly connected to each other or connected to each other via an intermediate element or device through electrical elements, electrical signals, or mechanical elements, depending on the particular context.

[0136] It will be appreciated that some embodiments can include one or more general-purpose or special-purpose processors (or "processing devices") such as microprocessors, digital signal processors, custom processors, and field programmable gate arrays (FPGAs), along with uniquely stored program instructions (including software and firmware), which control the one or more processors to implement some, most, or all of the functions of the methods and / or apparatuses described herein in conjunction with certain non-processor circuits. Alternatively, some or all of the functions can be implemented by a state machine without stored program instructions, or in one or more application specific integrated circuits (ASICs), where each function or some combination of certain functions is implemented as custom logic. Of course, a combination of these two methods can be used.

[0137] In addition, embodiments can be implemented as a computer-readable storage medium having computer-readable code stored thereon for programming a computer (e.g., including a processor) to perform the methods described and claimed herein. Any suitable computer-usable or computer-readable medium can be utilized. Examples of such computer-readable storage media include, but are not limited to, hard disks, CD-ROMs, optical storage devices, magnetic storage devices, ROM (read-only memory), PROM (programmable read-only memory), EPROM (erasable programmable read-only memory), EEPROM (electrically erasable programmable read-only memory), and flash memory. In the context of this document, a computer-usable or computer-readable medium can be any medium that can contain, store, communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device.

[0138] In addition, it can be expected that, when guided by the concepts and principles disclosed herein, although a large amount of effort and many design choices may be caused by, for example, available time, current technology, and economic considerations, a person of ordinary skill in the art will be able to easily generate such software instructions, programs, and ICs with a minimum of experimentation. For example, the computer program code for performing the operations of various exemplary embodiments can be written in an object-oriented programming language such as Java, Smalltalk, C++, Python, etc. However, the computer program code for performing the operations of various exemplary embodiments can also be written in a conventional procedural programming language such as the "C" programming language or a similar programming language. The program code can be executed entirely on a computer, partially on a computer, executed as a stand-alone software package, partially on a computer and partially on a remote computer or server, or entirely on a remote computer or server. In the latter scenario, the remote computer or server can be connected to the computer through a local area network (LAN) or a wide area network (WAN), or a connection to an external computer can be made (e.g., through the Internet using an Internet service provider).

[0139] The abstract of the present disclosure is provided to allow the reader to quickly understand the nature of the technical disclosure. It should be understood when submitting the abstract that the abstract will not be used to interpret or limit the scope or meaning of the claims. In addition, in the foregoing detailed description, it can be seen that, for the purpose of simplifying the disclosure, various features are combined in various embodiments. This method of disclosure should not be construed as reflecting an intention that the claimed embodiments require more features than are expressly recited in each claim. On the contrary, as reflected in the following claims, the inventive subject matter lies in less than all the features of a single disclosed embodiment. Accordingly, the following claims are hereby incorporated into the detailed description, where each claim stands on its own as a separately claimed subject matter.

Claims

1. A method, comprising: at a radio device, determining one or more conditions of a broadband network; at the radio device, receiving an access criterion from a narrowband network site of a narrowband network, the access criterion indicating that a subset of a plurality of radio devices can register with the narrowband network site to communicate on the narrowband network; and in response to the one or more conditions of the broadband network satisfying one or more given conditions and receiving the access criterion: when the radio device is communicating on the broadband network, continuing to communicate on the broadband network at the radio device; and when the radio device is communicating on the narrowband network or attempting to register with the narrowband network site, switching at the radio device from communicating on the narrowband network or attempting to register with the narrowband network site to communicating on the broadband network.

2. The method according to claim 1, further comprising: further in response to the one or more conditions of the broadband network satisfying the one or more given conditions and in response to one or more of the following, switching at the radio device from communicating on the narrowband network or attempting to register with the narrowband network site to communicating on the broadband network, the following including: being rejected from registering at the narrowband network site; determining that the narrowband network site is busy; determining a failure of talk group membership on the narrowband network; losing communication with a control channel on the narrowband network; determining that the control channel includes a shared control channel; and determining that there is no active connection on the narrowband network.

3. The method according to claim 1, further comprising: at the radio device, communicating on the broadband network; at the radio device, determining one or more respective conditions of the narrowband network; and in response to the one or more respective conditions of the narrowband network satisfying one or more respective given conditions and in response to one or more of the following, switching at the radio device from communicating on the broadband network to communicating on the narrowband network, the following including: determining that the broadband network has dropped; determining that there is no active connection with the broadband network; determining that there is no connection to the Internet on the broadband network; losing a connection with a call server on the broadband network, the call server being used to coordinate one or more calls and messages between the broadband network and the narrowband network; determining that the call server is unavailable; determining that the radio device has been deregistered from the call server; and determining that a gateway between the broadband network and the narrowband network is unavailable.

4. The method according to claim 1, wherein, the narrowband network includes one or more of a digital mobile radio network and a land mobile radio network.

5. The method according to claim 1, wherein, the broadband network includes one or more of a cellular telephone network, an LTE (Long Term Evolution) network, a 5G network, and a WiFi network.

6. The method according to claim 1, wherein: One or more conditions of the broadband network include one or more of the following: signal strength of the broadband network, signal quality of the broadband network, reference signal received power (RSRP) of the broadband network, received signal strength indicator (RSSI) of the broadband network, reference signal received quality (RSRQ) of the broadband network, identifier(s) of the broadband network and one or more of the broadband network sites, and The one or more given conditions each include one or more of the following: The signal strength of the broadband network is higher than a given signal strength threshold; The signal quality of the broadband network is higher than a given signal quality threshold; The RSRP of the broadband network is higher than a given RSRP threshold; The RSSI of the broadband network is higher than a given RSSI threshold; The RSRQ of the broadband network is higher than a given RSRQ threshold; The identifier is in an approved list; And The identifier is not in a rejection list.

7. The method according to claim 1, further comprising: After a given dwell time during which the radio device communicates on the narrowband network, at the radio device, switching from communicating on the narrowband network to communicating on the broadband network.

8. The method according to claim 1, wherein The access criterion includes an indication of identifiers of a subset of the plurality of radio devices, the subset of the plurality of radio devices being able to register with the narrowband network site to communicate on the narrowband network.

9. The method according to claim 1, further comprising: At the radio device, communicating on the broadband network; At the radio device, determining that the signal strength of the narrowband network is higher than a given signal strength threshold; At the radio device, receiving the access criterion from the narrowband network site; and When further access criterion is received from the narrowband network site, at the radio device, switching from communicating on the broadband network to communicating on the narrowband network, the further access criterion indicating that all radio devices are able to register on the narrowband network, not just the subset.

10. The method according to claim 1, wherein The subset includes the radio device, or The subset excludes the radio device.

11. A radio device, comprising: A communication unit configured to communicate via a narrowband network and a broadband network; And A controller configured to: Determine one or more conditions in the broadband network; Via the communication unit, receive an access criterion from a narrowband network site of the narrowband network, the access criterion indicating that a subset of a plurality of radio devices is able to register with the narrowband network site to communicate on the narrowband network; And In response to one or more conditions of the broadband network satisfying one or more given conditions and receiving the access criterion: When the radio device is communicating on the broadband network, continue to communicate on the broadband network via the communication unit; And When the radio device is communicating on the narrowband network or attempting to register with the narrowband network site, switch from communicating on the narrowband network or attempting to register with the narrowband network site to communicating on the broadband network via the communication unit.

12. The radio device according to claim 11, wherein, the controller is further configured to: further switch from communicating on the narrowband network or attempting to register with the narrowband network site to communicating on the broadband network in response to one or more conditions of the broadband network meeting the one or more given conditions and in response to one or more of the following: being rejected from registering at the narrowband network site; determining that the narrowband network site is busy; failing to determine talk group membership on the narrowband network; losing communication with the control channel on the narrowband network; determining that the control channel includes a shared control channel; and determining that there is no active connection on the narrowband network.

13. The radio device according to claim 11, wherein, the controller is further configured to: communicate on the broadband network at the radio device; determine one or more respective conditions of the narrowband network; and switch from communicating on the broadband network to communicating on the narrowband network in response to one or more respective conditions of the narrowband network meeting one or more respective given conditions and in response to one or more of the following: determining that the broadband network is down; determining that there is no active connection with the broadband network; determining that there is no connection to the Internet on the broadband network; losing connection with the call server on the broadband network, the call server coordinating one or more calls and messages between the broadband network and the narrowband network; determining that the call server is unavailable; determining that the radio device has been deregistered from the call server; and determining that the gateway between the broadband network and the narrowband network is unavailable.

14. The radio device according to claim 11, wherein, the narrowband network includes one or more of a digital mobile radio network and a land mobile radio network.

15. The radio device according to claim 11, wherein, the broadband network includes one or more of a cellular telephone network, an LTE (Long Term Evolution) network, a 5G network, and a WiFi network.

16. The radio device according to claim 11, wherein: one or more conditions of the broadband network include one or more of the following: the signal strength of the broadband network, the signal quality of the broadband network, the reference signal received power RSRP of the broadband network, the received signal strength indicator RSSI of the broadband network, the reference signal received quality RSRQ of the broadband network, the identifier of one or more of the broadband network and the broadband network site, and the one or more given conditions each include one or more of the following: the signal strength of the broadband network is higher than a given signal strength threshold; The signal quality of the broadband network is higher than a given signal quality threshold; The RSRP of the broadband network is higher than a given RSRP threshold; The RSSI of the broadband network is higher than a given RSSI threshold; The RSRQ of the broadband network is higher than a given RSRQ threshold; The identifier is in the approved list; and The identifier is not in the rejection list.

17. The radio device according to claim 11, wherein, The controller is further configured to: After a given dwell time in which the radio device communicates on the narrowband network, switch from communicating on the narrowband network to communicating on the broadband network.

18. The radio device according to claim 11, wherein, The access criterion includes an indication of identifiers of a subset of the plurality of radio devices, the subset of the plurality of radio devices being able to register with the narrowband network site to communicate on the narrowband network.

19. The radio device according to claim 11, wherein, The controller is further configured to: Communicate on the broadband network; Determine that the signal strength of the narrowband network is higher than a given signal strength threshold; Receive the access criterion from the narrowband network site; and When a further access criterion is received from the narrowband network site, switch from communicating on the broadband network to communicating on the narrowband network, the further access criterion indicating that all radio devices are able to register on the narrowband network, not just the subset.

20. The radio device according to claim 11, wherein, The subset includes the radio device, or the subset excludes the radio device.

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