Network control entity, access point and method for implementing access to wireless tags in a wireless communication network

Abstract

A method for implementing access to at least one wireless tag (301, 302, 303) in a wireless communication network (100) is provided, which is executed in a network control entity (103). The wireless communication network (100) includes two or more access points AP (110, 111, 112). The network control entity (103) configures at least one first AP (110, 111, 112) to transmit a radio frequency signal within a first time period (TS#3). In addition, the network control entity (103) configures at least one second AP (110, 111, 112) to receive at least one radio signal reflected from at least one wireless tag (301, 302, 303) using the transmitted radio frequency signal within the first time period (TS#3). A network control entity (103) for implementing access to at least one wireless tag (301, 302, 303) in a wireless communication network (100) is also provided. Further, an access point AP (110, 111, 112) and a method therein for implementing access to at least one wireless tag (301, 302, 303) in a wireless communication network (100) are also provided.

Description

Technical Field

[0001] Embodiments herein relate to wireless tags in a wireless communication network. Specifically, embodiments herein relate to a network control entity and method for enabling access to wireless tags in a wireless communication network. In addition, embodiments herein relate to an access point and method for enabling access to wireless tags in a wireless communication network. Background Art

[0002] One example of wireless tag or beacon technology is radio frequency identification (RFID). Generally, RFID uses an electromagnetic field emitted from an RFID reader to automatically identify and track wireless RFID tags.

[0003] Figure 1 An example of an RFID reader or interrogator 101 (e.g., a two-way radio transmitter-receiver) that sends a signal to and reads the response of a wireless tag 101 is shown. The response can provide electronically stored information in the wireless tag 101, such as, for example, information about the object to which it is attached. There are basically three types of wireless RFID tags: active RFID tags, semi-active RFID tags, and passive RFID tags. Active RFID tags include a local power source such as, for example, a battery, and can periodically send its ID signal. Active RFID tags can operate at distances of hundreds of meters from the RFID reader. Semi-passive RFID tags or battery-assisted passive (BAP) tags include a relatively small battery and are activated when an RFID reader is present. Passive RFID tags do not include a battery, but instead collect radio energy from the interrogation radio waves of a nearby RFID reader. The collected radio energy is then used to modulate the interrogation radio waves into a response at the same frequency. Since it has no battery, passive RFID tags are generally cheaper and smaller than active RFID tags or semi-active RFID tags.

[0004] Passive RFID tags can include at least three parts: an integrated circuit for storing and processing information for modulating and demodulating radio frequency (RF) signals; means for collecting DC power from the incident radio signals of the RFID reader; and an antenna for receiving and transmitting radio signals. Passive RFID tags can also include fixed logic or programmable logic for processing transmission and sensor data, respectively.

[0005] Another example of wireless tagging or beaconing technology is backscatter. While RFID is single-static radio communication, i.e., the RFID reader both transmits and receives signals from the wireless RFID tag, backscatter can use double-static radio communication. Double-static radio communication means that a transmitter can be used to send a radio signal to the wireless tag, while another device, i.e., the receiver or reader, receives the response from the wireless tag. Thus, the receiver and transmitter can be two different devices located at different positions. Similar to RFID, backscatter wireless tags can also be active, semi-passive, or passive.

[0006] Figure 2 An example is shown of a transmitter 201 (e.g., an RF signal generator) that sends a radio signal to a wireless tag 202 and a receiver 203 that receives the backscattered response signal from the wireless tag 202. The backscattered response signal is generated by the wireless tag 202 by modulating its information onto the reflection coefficient of its reflection of the transmitted radio signal. Due to their low cost and low power consumption, passive and / or semi-passive backscatter wireless tags are promising for Internet of Things (IoT) enabled devices. However, a problem is how to enable such wireless tags to operate in a wireless communication network. SUMMARY OF THE INVENTION

[0007] The aim of embodiments herein is to enable a wireless tag to operate in a wireless communication network.

[0008] According to a first aspect of embodiments herein, this aim is achieved by a method for enabling access to at least one wireless tag in a wireless communication network, performed by a network control entity. The wireless communication network includes two or more access points (APs). The network control entity configures at least one first AP to transmit a radio frequency signal during a first time period. Additionally, the network control entity configures at least one second AP to receive at least one radio signal reflected from at least one wireless tag using the transmitted radio frequency signal during the first time period.

[0009] According to a second aspect of embodiments herein, this aim is achieved by a network control entity for enabling access to at least one wireless tag in a wireless communication network. The wireless communication network includes two or more access points (APs). The network control entity is adapted to configure at least one first AP to transmit a radio frequency signal during a first time period. The network control entity is also adapted to configure at least one second AP to receive at least one radio signal reflected from at least one wireless tag using the transmitted radio frequency signal during the first time period.

[0010] According to a third aspect of the embodiments herein, this object is achieved by a method for enabling access to at least one wireless tag in a wireless communication network, performed by an access point (AP). The AP obtains configuration information. Further, the AP transmits a radio frequency signal within a first time period based on the obtained configuration information, or receives at least one radio signal reflected from at least one wireless tag using the transmitted radio frequency signal within the first time period.

[0011] According to a fourth aspect of the embodiments herein, this object is achieved by an access point (AP) for enabling access to at least one wireless tag in a wireless communication network. The AP is adapted to obtain configuration information. Based on the obtained configuration information, the AP is adapted to transmit a radio frequency signal within a first time period, or receive at least one radio signal reflected from at least one wireless tag using the transmitted radio frequency signal within the first time period.

[0012] According to a fifth aspect of the embodiments herein, there is also provided a computer program configured to execute the method described above. Further, according to a sixth aspect of the embodiments herein, there is also provided a carrier configured to carry the computer program, the computer program being configured to execute the method described above.

[0013] Multi-static backscatter radio communication is implemented in a wireless communication network by configuring at least one AP in the wireless communication network to transmit a radio frequency signal within a specified time period, and configuring at least one other AP in the wireless communication network to receive the reflected response from the wireless tag during the same specified time period. Specifically, it enables scheduling and multiplexing of wireless tags in the wireless communication network. Thus, multi-static backscatter radio communication can refer here to the ability to provide multiple access to wireless tags in a wireless communication network and the interoperability of the wireless tags with other wireless nodes in the wireless communication network. Thereby, enabling the wireless tags to operate in the wireless communication network. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The features and advantages of the embodiments will become apparent to those skilled in the art from the following detailed description of exemplary embodiments with reference to the accompanying drawings, in which:

[0015] Figure 1 is a schematic diagram of RFID radio communication;

[0016] Figure 2 is a schematic diagram of backscatter radio communication;

[0017] Figure 3 is a schematic diagram of a wireless tag in a wireless communication network according to some embodiments;

[0018] Figure 4Schematic diagram of the frequency shift effect of the reflected signal according to some embodiments;

[0019] Figure 5 Flowchart depicting an embodiment of a method in a network control entity;

[0020] Figure 6 Flowchart depicting an embodiment of a method in an AP;

[0021] Figure 7 Schematic diagram of an example of the UL / DL configuration of an AP according to some embodiments;

[0022] Figure 8 Schematic diagram of the frequencies allocated during a first time period according to some embodiments;

[0023] Figure 9 Block diagram depicting an embodiment of a network control entity;

[0024] Figure 10 Block diagram depicting an embodiment of an AP. Detailed Description

[0025] For clarity, the drawings are schematic and simplified, and they only show the details essential for understanding the embodiments presented herein, while other details have been omitted. Throughout the text, the same reference numerals are used for the same or corresponding components or steps.

[0026] Figure 3 Depicts an example of a wireless communication network 100 in which the embodiments herein can be implemented. The wireless communication network 100 can be any wireless system or cellular network, such as a Long Term Evolution (LTE) network, any 3rd Generation (3 Figure 3 , ,

[0026] , , Figure 10 , ,

[0027] , Figure 3 , , rd ,

[0025] , ,

[0024] ) Partnership Project (3GPP) cellular network, Worldwide Interoperability for Microwave Access (Wimax) network, Wireless Local Area Network (WLAN / Wi-Fi), 4th Generation (4G) or LTE Advanced network, 5th Generation (5G) or New Radio (NR) network, etc.

[0027] The wireless communication network 100 can include multiple access points (APs), where in Figure 3The example depicts three access points (APs), namely AP 110, AP 111, and AP 112. AP 110, 111, 112 are operable or adapted to serve wireless devices located within their radio coverage. AP 110, 111, 112 may be referred to as network nodes, network access nodes, radio nodes, or base stations, and may be, for example, any one of eNB, gNB, eNodeB, gNodeB, home NodeB, home eNodeB, or home gNodeB, etc. AP 110, 111, 112 may also be any type of local access point, such as an access point for WiFi or WLAN. Further, it should be noted that AP 110, 111, 112 may also be adapted to implement other known radio communication technologies, such as, for example, Bluetooth, Multefire, ZigBee, etc. According to some embodiments, some of AP 110, 111, 112 may be configured to transmit radio frequency signals in the wireless communication network 100. This is indicated by Figure 3 the fully drawn arrows in.

[0028] Multiple wireless tags may operate in the wireless communication network 100, where three are depicted in Figure 3 , namely, wireless tag 301, wireless tag 302, and wireless tag 303. Wireless tags 301, 302, 303 may be any type of reflective or backscatter-enabled wireless tags, where the wireless tags are preferably passive wireless tags and / or semi-passive wireless tags. It should also be noted that wireless tags 301, 302, 303 may also be implemented as part of any type of wireless device or IoT-enabled device, such as, for example, IoT sensors, IoT wearable devices, or other IoT devices, etc. Further, a wireless device may herein refer to any type of wireless device or user equipment (UE) that communicates with a network node and / or with another wireless device in a cellular, mobile, or radio communication network or system. Examples of such wireless devices are mobile phones, cellular phones, personal digital assistants (PDAs), smart phones, tablets, sensors equipped with UEs, laptop-mounted devices (LME) (e.g., USB), laptop-embedded devices (LEE), machine type communication (MTC) devices or machine-to-machine (M2M) devices, customer premise equipment (CPE), device-to-device (D2D) wireless devices, wireless devices capable of machine-to-machine (M2M) communication, etc. As Figure 3 shown, wireless tags 301, 302, 303 may be configured to receive radio frequency signals from AP 110, 111, 112. Wireless tags 301, 302, 303 may also respond to the transmitted radio frequency signals by reflecting (i.e., backscattering) the radio frequency signals to AP 110, 111, 112. This is indicated byFigure 3 is represented by the dashed arrows in. According to some embodiments, some of the APs 110, 111, 112 may be configured to receive at least one radio signal reflected (i.e., backscattered) from the wireless tags 301, 302, 303.

[0029] In addition, according to some embodiments, the wireless communication network 100 may further include a network control entity 103. The network control entity 103 is operable or adapted to communicate with and configure the APs 110, 111, 112. The network control entity 103 may also be collocated with, included in, or form part of one or more of the APs 110, 111, 112 in the wireless communication network 100. Optionally, the network control entity 103 may also be provided as a service by a remote data processing network (not shown).

[0030] Although the following embodiments are described with reference to Figure 3 this should not be construed as a limitation on the embodiments herein, but merely as an example for illustrative purposes.

[0031] As part of the development of the embodiments described herein, it has been recognized that in addition to modulating its information on the reflected or backscattered radio signal from the received radio frequency signal, some wireless tags are also capable of shifting the frequency center of the reflected radio signal away from the frequency center of the received radio frequency signal. This is particularly true for inexpensive and low-complexity wireless tags (such as, for example, passive and semi-passive wireless backscatter tags) because these wireless tags typically perform signal modulation of the received radio frequency signal directly at the passband.

[0032] Figure 4 illustrates an example of the effect of signal modulation of a received radio frequency RF signal directly at the passband. As Figure 4 shown, the RF signal has a frequency center f. Since the wireless tag can shift the frequency center of the reflected radio signal by a specific amount Δf, the reflected radio signal of the wireless tag may include two reflection coefficients or reflected images, namely, f - Δf and f + Δf.

[0033] Therefore, according to the embodiments herein, by configuring at least one AP in the wireless communication network to transmit a radio frequency signal during a specified period of time, and configuring at least one other AP in the wireless communication network to receive the reflected response from the wireless tag during the same specified period of time, this characteristic of the wireless tag can be used to provide multiple access to the wireless tags in the wireless communication network. Embodiments of the network control entity, the AP, and their methods will be described below with reference toFigures 5 to 10 be described in more detail.

[0034] Reference will now be made to Figure 5 the flowchart depicted in

[0035] Figure 5 to illustrate an example of an action or operation that can be taken by the network control entity 103 in the wireless communication network 100.

[0036] Action 501

[0037] Optionally, the network control entity 103 may assign a frequency shift to each of the at least one wireless tag 301, 302, 303, respectively. The assigned frequency shift will be used by the at least one wireless tag 301, 302, 303 when using the transmitted radio frequency signal to reflect a radio signal. This means that the network control entity 103 may assign a unique frequency shift Δf to each of the wireless tags 301, 3, 303 in the wireless communication network 100 n . Here, n = 1, 2, …, N, where N may be the total number of wireless tags to which a frequency shift can be assigned within the determined total frequency bandwidth (e.g., Figure 8 ΔF in Figure 3 ). The determined total frequency bandwidth may be the radio resources or frequency resources available for or allocated to the wireless tags in the wireless communication network 100. For example, in the wireless communication network 100 shown in Figure 8 , this means that the wireless tag 301 may be assigned a frequency shift of, for example, Figure 8 Δf1 in Figure 8The frequency shift of Δf3 therein. A frequency shift such as Δf is assigned to each of the wireless tags 301, 302, 303. n The assignment of the frequency shift can be performed statically, semi-statically or dynamically by the network control entity 103.

[0038] The network control entity 103 can also notify each of the APs 110, 111, 112 of the assignment of the frequency shift for each of at least one of the wireless tags 301, 302, 303. In this case, this also means that the radio resources or frequency resources to be used when at least one of the wireless tags 301, 302, 303 reflects (i.e., backscatters) a radio signal using a radio frequency signal to be transmitted in the wireless communication network 100 can be notified to each of the APs 110, 111, 112.

[0039] Action 502

[0040] After the assignment in Action 501, the network control entity 103 can configure one or more of the APs 110, 111, 112 to configure at least one of the wireless tags 301, 302, 303 to reflect a radio signal by shifting the transmitted radio frequency signal according to the respectively assigned frequency shift. This means that the network control entity 103 can configure one or more of the APs 110, 111, 112 to send information to one or more of at least one of the wireless tags 301, 302, 303, the information indicating that one or more of at least one of the wireless tags 301, 302, 303 will reflect a radio signal by shifting the transmitted radio frequency signal according to its respectively assigned frequency shift Δf n The information can include the respectively assigned frequency shift Δf of one or more of at least one of the wireless tags 301, 302, 303. n .

[0041] Action 503

[0042] Optionally, the network control entity 103 can determine that at least one first AP 110, 111, 112 is to transmit a radio frequency signal during a first time period, and at least one second AP 110, 111, 112 is to receive at least one radio signal reflected from at least one of the wireless tags 301, 302, 303 using the transmitted radio frequency signal during the first time period. This means that the network control entity 103 can assign different tasks to different APs 110, 111, 112, whereby some of the APs 110, 111, 112 can be assigned to transmit radio frequency signals, while some of the APs 110, 111, 112 can be assigned to receive at least one radio signal (i.e., backscattered) reflected from at least one of the wireless tags 301, 302, 303.

[0043] In some embodiments, the network control entity 103 may group each of at least one first AP 110, 111, 112 into a transmit (TX) group. Each of at least one first AP 110, 111, 112 in the TX group may also synchronize their downlink (DL) time periods and transmit their radio frequency signals simultaneously. In addition, the network control entity 103 may group each of at least one second AP 110, 111, 112 into a receive (RX) group. Each of at least one second AP 110, 111, 112 in the RX group may also synchronize their uplink (UL) time periods and receive the reflected radio signals from at least one of the wireless tags 301, 302, 303 simultaneously. This means that the network control entity 103 can coordinate and synchronize the transmission of radio frequency signals and the reception of reflected radio signals by the APs 110, 111, 112 in the wireless communication network 100.

[0044] Action 504

[0045] The network control entity 103 configures at least one first AP 110, 111, 112 to transmit radio frequency signals within a first time period. This means that the network control entity 103 can configure at least one first AP 110, 111, 112 as a transmitter and transmit radio frequency signals simultaneously with other transmitting APs among at least one first AP 110, 111, 112 within a determined first time period. The radio frequency signals transmitted from each of at least one first AP 110, 111, 112 configured to transmit radio frequency signals are the same or at least very similar. The latter means that the radio frequency signals are transmitted from each of at least one first AP on the same or at least approximately the same frequency resources or radio resources in the wireless communication network 100. In some embodiments, this means that the radio frequency signals transmitted from each of one or more APs 110, 111, 112 configured to transmit radio frequency signals may be transmitted in the same determined DL time slot. This is further illustrated in the following Figures 7 to 8 and is further exemplified below. In some embodiments, the transmitted radio signals may be radio signals that do not include information, i.e., are only used to power the wireless tags 301, 302, 303. Alternatively, the transmitted radio signals may also include information to the wireless tags 301, 302, 303. In some embodiments, the transmitted radio frequency signals may be modulated radio frequency (RF) carriers.

[0046] In some embodiments, the network control entity 103 may configure at least one of the first APs 110, 111, 112 to also avoid transmitting on a subset of the frequency resources assigned to at least one of the wireless tags 301, 302, 303 during a first time period. This means that the network control entity 103 may configure the transmitting AP to remain silent during the first time period, i.e., not perform any transmission on any frequency resource or radio resource outside of the frequency resource or radio resource (e.g., f) used for transmitting radio frequency signals during the first time period. Optionally, in the case where a determined set of frequency resources (such as, for example Figure 8 ΔF in) is used to allocate frequency resources to at least one of the wireless tags 301, 302, 303, the network control entity 103 may configure the transmitting AP to remain silent on any frequency resource or radio resource within the determined set of frequency resources outside of the frequency resource or radio resource (e.g., Figure 8 f in) used for transmitting radio frequency signals during the first time period. This can be performed so that the reception of the reflected radio signals in the subset of the frequency resources assigned to at least one of the wireless tags 301, 302, 303 at the receiving AP in the wireless communication network 100 is not interfered with or does not cause noise.

[0047] In some embodiments, the network control entity 103 may configure at least one of the first APs 110, 111, 112 to transmit a scheduling grant to at least one of the wireless tags 301, 302, 303 during a second time period prior to the first time period, the scheduling grant indicating that a transmitted radio frequency signal is expected during the first time period. This means that the network control entity 103 may configure the transmitting AP to prepare and schedule some or all of at least one of the wireless tags 301, 302, 303 to receive a transmitted radio frequency signal during a first determined time period.

[0048] Action 505

[0049] The network control entity 103 configures at least one of the second APs 110, 111, 112 to receive at least one radio signal reflected from at least one of the wireless tags 301, 302, 303 using the transmitted radio frequency signal during the first time period. This means that the network control entity 103 may configure one or more of the APs 110, 111, 112 as receivers and, together with other receivers among one or more of the APs 110, 111, 112, simultaneously receive at least one radio signal (i.e., backscattered) reflected from at least one of the wireless tags 301, 302, 303 using the transmitted radio frequency signal during a determined first time period.

[0050] In some embodiments, the network control entity 103 may configure at least one of the second APs 110, 111, 112 to allocate two frequency resource subsets within a determined frequency resource set to at least one of the wireless tags 301, 302, 303 during a first time period. This means that the network control entity 103 may configure the receiving APs to receive reflected (i.e., backscattered) radio signals from at least one of the wireless tags 301, 302, 303 in each of the two frequency resource subsets (i.e., RF subchannel pairs, such as f-Δf n and f+Δf n ) respectively allocated to at least one of the wireless tags 301, 302, 303. It should also be noted that, optionally, the network control entity 103 may configure the receiving APs to receive reflected (i.e., backscattered) radio signals from at least one of the wireless tags 301, 302, 303 using only one of the two respectively allocated frequency resource subsets. Thus, in some embodiments, the network control entity 103 may also configure at least one of the second APs 110, 111, 112 to receive at least one radio signal reflected from at least one of the wireless tags 301, 302, 303 in at least one of the two allocated frequency resource subsets during the first time period.

[0051] Now, an example of an embodiment of a method for implementing access to at least one of the wireless tags 301, 302, 303 in the wireless communication network 100 performed by the access points (APs) 110, 111, 112 will be described with reference to the flowchart depicted in Figure 6 . Figure 6 FIG. is an example illustration of actions or operations that may be taken by one or more of the access points (APs) 110, 111, 112 in the wireless communication network 100.

[0052] Action 601

[0053] The APs 110, 111, 112 obtain configuration information. This means that the actions or operations of the APs 110, 111, 112 may be controlled by the network control entity 103 because the configuration information may be sent from the network control entity 103 to the APs 110, 111, 112. Optionally, the configuration information may be information that already exists in the APs 110, 111, 112, such as, for example, parameters preconfigured in the APs 110, 111, 112. In this case, the APs 110, 111, 112 do not have to receive any configuration information from the network control entity 103 to control or adjust the functions of the APs 110, 111, 112 because this has already been determined in the APs 110, 111, 112.

[0054] In some embodiments, the obtained configuration information may indicate that APs 110, 111, 112 are to transmit radio frequency signals during a first time period, or may indicate that APs 110, 111, 112 are to receive at least one radio signal reflected from at least one wireless tag 301, 302, 303 using the transmitted radio frequency signals during the first time period. This means that APs 110, 111, 112 can be configured by network control entities 101, 110, 111, 112 to operate either as transmitters or as receivers in the wireless communication network 100 during the first time period. In some embodiments, the obtained configuration information may further indicate that APs 110, 111, 112 configure at least one wireless tag 301, 302, 303 to reflect radio signals by shifting the transmitted radio frequency signals according to respectively assigned frequency shifts (e.g., Δf n ). This information may include the respectively assigned frequency shifts (e.g., Δf n ) of at least one wireless tag 301, 302, 303, for example, if this is unknown to APs 110, 111, 112.

[0055] Action 602

[0056] After obtaining the configuration information in action 601, APs 110, 111, 112 can configure at least one wireless tag 301, 302, 303 to reflect radio signals by shifting the transmitted radio frequency signals according to respectively assigned frequency shifts. This means that APs 110, 111, 112 can send information to one or more of at least one wireless tag 301, 302, 303 that indicates that the one or more wireless tags 301, 302, 303 will reflect radio signals by shifting the transmitted radio frequency signals according to their respectively assigned frequency shifts (e.g., Δf n ). This information may include the respectively assigned frequency shifts (e.g., Δf n ) of at least one wireless tag 301, 302, 303, for example, if this is unknown to at least one wireless tag 301, 302, 303. This can be performed in response to the obtained configuration information in action 601.

[0057] Action 603

[0058] Optionally, when APs 110, 111, 112 are to transmit radio frequency signals during a first time period, APs 110, 111, 112 may synchronize their downlink (DL) time periods with one or more APs 110, 111, 112 in the wireless communication network 100 that are also configured to transmit radio frequency signals during the first time period. This means that, for example, the transmitting APs 110, 111, 112 in the wireless communication network 100 may synchronize their DL time slots to ensure that they can transmit their radio frequency signals simultaneously.

[0059] Action 604

[0060] According to some embodiments, when APs 110, 111, 112 are to transmit radio frequency signals during a first time period, APs 110, 111, 112 may send a scheduling grant to at least one wireless tag 301, 302, 303 during a second time period before the first time period, the scheduling grant indicating that a radio frequency signal is expected during the first time period. Accordingly, the transmitting APs in the wireless communication network 100 may prepare and schedule some or all of at least one wireless tag 301, 302, 303 to receive the transmitted radio frequency signals during the first time period.

[0061] Action 605

[0062] Based on the obtained configuration information in Action 601, APs 110, 111, 112 may transmit radio frequency signals during the first time period. This means that APs 110, 111, 112 are configured as transmitters via the obtained information and transmit radio frequency signals during the first time period simultaneously with other transmitting APs among one or more APs 110, 111, 112.

[0063] Action 606

[0064] According to some embodiments, when APs 110, 111, 112 are to transmit radio frequency signals during a first time period, APs 110, 111, 112 may avoid transmitting during the first time period on a subset of frequency resources allocated to at least one wireless tag 301, 302, 303. This may be performed so that the reception of reflected radio signals in a subset of frequency resources (e.g., f - Δf n and f + Δf n ) allocated to at least one wireless tag 301, 302, 303 at a receiving AP in the wireless communication network 100 is not interfered with or does not cause noise.

[0065] Action 607

[0066] In some embodiments, when APs 110, 111, 112 are to receive at least one reflected radio signal during a first time period, APs 110, 111, 112 may synchronize their uplink (UL) time periods with one or more APs 110, 111, 112 in the wireless communication network 100 that are also configured to receive at least one reflected radio signal during the first time period. This means that, for example, the receiving APs 110, 111, 112 in the wireless communication network 100 may synchronize their UL time slots to ensure that they can receive at least one reflected radio signal during the first time period.

[0067] Action 608

[0068] In some embodiments, when APs 110, 111, 112 are to receive at least one reflected radio signal during a first time period, APs 110, 111, 112 may allocate two frequency resource subsets within a determined set of frequency resources to at least one wireless tag 301, 302, 303 during the first time period. This means that APs 110, 111, 112 may receive reflected (i.e., backscattered) radio signals from at least one wireless tag 301, 302, 303 in each of the two respectively allocated frequency resource subsets (e.g., f - Δf n and f + Δf n ) of at least one wireless tag 301, 302, 303. It should also be noted that, optionally, APs 110, 111, 112 may use only one of the two respectively allocated frequency resource subsets to receive reflected (i.e., backscattered) radio signals from at least one wireless tag 301, 302, 303. Thus, in some embodiments, APs 110, 111, 112 may receive at least one radio signal reflected from at least one wireless tag 301, 302, 303 in at least one of the two allocated frequency resource subsets during the first time period.

[0069] Action 609

[0070] Based on the obtained configuration information in Action 601, APs 110, 111, 112 may receive at least one radio signal reflected from at least one wireless tag 301, 302, 303 using the transmitted radio frequency signal during the first time period. This means that APs 110, 111, 112 may be configured as receivers via the obtained information and receive at least one radio signal reflected (i.e., backscattered) from at least one wireless tag 301, 302, 303 using the transmitted radio frequency signal during a determined first time period simultaneously with other receiving APs among one or more APs 110, 111, 112.

[0071] It should also be noted that the receiving APs in the wireless communication network 100 (e.g., all APs in the RX group) can exchange information about at least one radio signal they receive. This can be performed to improve the detection performance of radio signals in the wireless communication network 100. According to some embodiments, this can be performed using so-called chase combining of the received radio signals. Optionally, this can be performed by the network control entity 103. In this case, the received radio signals in each or some of the receiving APs in the wireless communication network 100 can be sent to the network control entity 103 for detection.

[0072] Figure 7 A schematic diagram showing an example of the UL / DL configuration of APs 110, 111, 112 according to some embodiments is shown. In this example, APs 110 and 112 are configured to transmit radio frequency signals on the downlink in time slot TS#3. During the same period, i.e., in time slot TS#3, AP 111 is configured to receive at least one radio signal reflected (i.e., backscattered) from at least one of the wireless tags 301, 302, 303. The at least one radio signal is reflected by the at least one wireless tag 301, 302, 303 using the transmitted radio frequency signals. This means that the wireless tags 301, 302, 303 can use the energy of the transmitted radio frequency signals from APs 110 and 112 to generate radio signals reflected from the wireless tags 301, 302, 303 that will be received by AP 111 within the same time slot TS#3. Optionally, in an earlier time slot TS#1 or TS#2 (i.e., a time slot before time slot TS#3), APs 110 and 112 can be configured to send a scheduling grant to at least one of the wireless tags 301, 302, 303, which indicates that radio frequency signals are expected in time slot TS#3.

[0073] Figure 8 A schematic diagram showing radio resource allocation (i.e., allocated frequencies) within a first period (such as, for example, Figure 7 time slot TS#3 in) according to some embodiments is shown. According to this example, all transmitting APs in the wireless communication network 100 (such as, for example, Figure 7 APs 110 and 112 in) are configured to simultaneously transmit radio frequency signals on radio resource or frequency resource f in time slot TS#3.

[0074] During the same period, i.e., in time slot TS#3, all receiving APs in the wireless communication network 100 (such as, for example, Figure 7 AP 111 in) are configured to be in the wireless communication network 100 at the wireless tags 301, 302, 303 respectively allocated radio resources or frequency resources (i.e., f - Δfn and f + Δf n ) receives radio signals reflected (i.e., backscattered) from the wireless tags 301, 302, 303. For example, in all receiving APs in the wireless communication network 100 (such as, for example Figure 7 AP111 in), the wireless tag 301 may be assigned radio resources or frequency resources f - Δf1 and f + Δf1, while the wireless tag 302 may be assigned radio resources or frequency resources f - Δf2 and f + Δf2, and the wireless tag 303 may be assigned radio resources or frequency resources f - Δf3 and f + Δf3. This means that since the wireless tags 301, 302, 303 will perform frequency shifts of the transmitted radio signal f according to their assigned frequency shifts Δf1, Δf2, and Δf3 respectively, and modulate their information onto the reflected radio signals, the receiving APs in the wireless communication network 100 (such as, for example Figure 7 AP 111 in) are adapted to receive the reflected signals from each of the wireless tags 301, 302, 303 in their respectively assigned radio resources or frequency resources f - Δf1 and f + Δf1, f - Δf2 and f + Δf2, and f - Δf3 and f + Δf3. This example can be extended to any number of wireless tags within the determined set of frequency resources ΔF assigned to the wireless tags in the wireless communication network 100.

[0075] According to some embodiments, the radio resources or frequency resources f - Δf1 and f + Δf1, f - Δf2 and f + Δf2, and f - Δf3 and f + Δf3 assigned to the wireless tags 301, 302, 303 are non - overlapping.

[0076] To perform method actions in the network control entity 103 to enable access to at least one of the wireless tags 301, 302, 303 in the wireless communication network 100, where the wireless communication network 100 includes two or more access points (APs) 110, 111, 112, the network control entity 103 may include Figure 9 the following arrangements depicted in. Figure 9 FIG. shows a schematic block diagram of an embodiment of the network control entity 103 as an independent unit adapted to be connected to the wireless communication network 100. However, it should also be noted that the network control entity 103 may also be included in one or more of the APs 110, 111, 112, or form a part of one or more of the APs 110, 111, 112. Alternatively, the network control entity 103 may be provided as a service by a remote data - processing network.

[0077] The network control entity 103 may include a processing circuit 910 and a memory 920. It should be noted that some or all of the functions described as being performed by the network control entity 103 in the above embodiments may be provided by the processing circuit 910 that executes instructions stored on a computer-readable medium (such as, for example Figure 9 the memory 920 shown). The processing circuit 910 may further include a receiving module 911 and a transmitting module 912. The receiving module 911 and the transmitting module 912 may also form part of a single transceiver. The receiving module 911 and the transmitting module 912 may be adapted to communicate with two or more access points (APs) 110, 111, 112 in the wireless communication network 100. Alternative embodiments of the network control entity 103 may include additional components such as, for example, a configuration module 913, an allocation module 914, a determination module 915, and a packet module 916, each responsible for providing their respective corresponding functions necessary to support the embodiments described herein.

[0078] The network control entity 103 or the processing circuit 910 is adapted to perform the following operations, or may include a configuration module 913 adapted to perform the following operations: configure at least one first AP 110, 111, 112 to transmit radio frequency signals during a first time period. Additionally, the network control entity 103 or the processing circuit 910 is adapted to perform the following operations, or may include a configuration module 913 adapted to perform the following operations: configure at least one second AP 110, 111, 112 to receive at least one radio signal reflected from at least one wireless tag 301, 302, 303 using the transmitted radio frequency signals during the first time period.

[0079] In some embodiments, the network control entity 103 or the processing circuit 910 may be adapted to perform the following operations, or may include a configuration module 913 adapted to perform the following operations: configure at least one second AP 110, 111, 112 to allocate two frequency resource subsets (e.g., f - Δf n and f + Δf n ) within a determined set of frequency resources (e.g., ΔF) to at least one wireless tag 301, 302, 303 during a first time period. In this case, according to some embodiments, the network control entity 103 or the processing circuit 910 may be adapted to perform the following operations, or may include a configuration module 913 adapted to perform the following operations: configure at least one second AP 110, 111, 112 to, during the first time period, within the two allocated frequency resource subsets (e.g., f - Δf n and f + Δf n) receive at least one radio signal reflected from at least one of the wireless tags 301, 302, 303. Additionally, in some embodiments, the network control entity 103 or the processing circuit 910 may be adapted to perform the following operations, or may include a configuration module 913 adapted to perform the following operations: configure at least one of the first APs 110, 111, 112 to avoid transmitting during a first time period on a subset of frequency resources (e.g., f - Δf n and f + Δf n ) allocated to at least one of the wireless tags 301, 302, 303. Additionally, in some embodiments, the network control entity 103 or the processing circuit 910 may be adapted to perform the following operations, or may include a configuration module 913 adapted to perform the following operations: configure at least one of the first APs 110, 111, 112 to send a scheduling grant to at least one of the wireless tags 301, 302, 303 during a second time period prior to the first time period, the scheduling grant indicating that a transmitted radio frequency signal is expected during the first time period. Here, it should also be noted that the configuration performed by the network control entity 103 may be executed by sending configuration information to two or more access points (APs) 110, 111, 112 in the wireless communication network 100.

[0080] In some embodiments, the network control entity 103 or the processing circuit 910 may be adapted to perform the following operations, or may include an allocation module 914 adapted to perform the following operations: allocate a frequency shift (e.g., Δf n ) to at least one of the wireless tags 301, 302, 303, wherein the allocated frequency shift (e.g., Δf n ) will be used by at least one of the wireless tags 301, 302, 303 when reflecting radio signals using the transmitted radio frequency signal. Here, in some embodiments, the network control entity 103 or the processing circuit 910 may be adapted to perform the following operations, or may include a configuration module 913 adapted to perform the following operations: configure one or more of at least one of the first APs and / or the second APs 110, 111, 112 to configure at least one of the wireless tags 301, 302, 303 to reflect radio signals by shifting the transmitted radio frequency signal according to the respectively allocated frequency shift (e.g., Δf n ).

[0081] In addition, in some embodiments, the network control entity 103 or the processing circuit 910 may be adapted to perform the following operations, or may include a determination module 915 adapted to perform the following operations: determining that at least one of the first APs 110, 111, 112 is to transmit radio frequency signals during a first time period, and that at least one of the second APs 110, 111, 112 is to receive at least one radio signal reflected from at least one of the wireless tags 301, 302, 303 using the transmitted radio frequency signals during the first time period.

[0082] In addition, in some embodiments, the network control entity 103 or the processing circuit 910 may be adapted to perform the following operations, or may include a grouping module 916 adapted to perform the following operations: grouping each of at least one of the first APs 110, 111, 112 into a transmit (TX) group, wherein each of at least one of the first APs 110, 111, 112 in the TX group synchronizes their downlink (DL) time periods and transmits their radio frequency signals simultaneously. In addition, the network control entity 103 or the processing circuit 910 may be adapted to perform the following operations, or may include a grouping module 916 adapted to perform the following operations: grouping each of at least one of the second APs 110, 111, 112 into a receive (RX) group, wherein each of at least one of the second APs 110, 111, 112 in the RX group synchronizes their uplink (UL) time periods and receives the reflected radio signals from at least one of the wireless tags 301, 302, 303 simultaneously.

[0083] In addition, the embodiments described above for implementing access to at least one of the wireless tags 301, 302, 303 in the wireless communication network 100 may be implemented by one or more processing circuits (such as, for example Figure 9 the processing circuit 910 in the network control entity 103 depicted in) and computer program code for performing the functions and actions of the embodiments herein. The program code mentioned above may also be provided as a computer program product, for example in the form of a data carrier carrying the computer program code, or in the form of code means for performing the embodiments herein when loaded into the processing circuit 910 in the network control entity 103. The computer program code may be provided, for example, as pure program code in the network control entity 103 or on a server, and downloaded to the network control entity 103. Therefore, it should be noted that in some embodiments, the modules of the network control entity 103 may be implemented as computer programs stored in a memory 920 of a memory module such as Figure 9 for execution by a processing circuit or a processing module of the processing circuit 910 such as Figure 9

[0084] Those skilled in the art will also understand that the processing circuitry 910 and the memory 920 described above may refer to a combination of analog and digital circuitry, and / or one or more processors configured with software and / or firmware, such as that stored in the memory, which, when executed by one or more processors such as the processing circuitry 910, perform as described above. One or more of these processors and other digital hardware may be included in a single application specific integrated circuit (ASIC), or several processors and various digital hardware may be distributed among several separate components, whether individually packaged or assembled into a system on a chip (SoC).

[0085] To perform method acts in access points (APs) 110, 111, 112 to enable access to at least one wireless tag 301, 302, 303 in the wireless communication network 100, the APs 110, 111, 112 may include Figure 10 the following arrangements depicted in Figure 10 FIG. shows a schematic block diagram of an embodiment of the APs 110, 111, 112.

[0086] The APs 110, 111, 112 may include processing circuitry 1010, a memory 1020, and one or more antennas (not shown). It should also be noted that some or all of the functions described above as being performed by the APs 110, 111, 112 may be provided by processing circuitry 1010 executing instructions stored on a computer-readable medium, such as, for example Figure 10 the memory 1020 shown in. The APs 110, 111, 112 and / or the processing circuitry 1010 may also include a receiving module 1011 and a transmitting module 1012. The receiving module 1011 and the transmitting module 1012 may include radio frequency (RF) circuitry and baseband processing circuitry capable of transmitting and receiving radio signals in the wireless communication network 100. The receiving module 1011 and the transmitting module 1012 may also form part of a single transceiver. Further, the receiving module 1011 and the transmitting module 1012 may be adapted to communicate with a network control entity 103 and / or other access points (APs) 110, 111, 112 in the wireless communication network 100, for example, via a wired connection or an optical fiber connection. Alternative embodiments of the APs 110, 111, 112 and / or the processing circuitry 1010 may include additional components such as, for example, a synchronization module 1013, an allocation module 1014, and a configuration module 1015, each responsible for providing their respective corresponding functions necessary to support the embodiments described herein.

[0087] APs 110, 111, 112 or processing circuitry 1010 is adapted to obtain configuration information, or may include a receiving module 1011 adapted to obtain configuration information. Further, APs 110, 111, 112 or processing circuitry 1010 is adapted to perform the following operations, or may include a transmitting module 1012 and / or a receiving module 1011 adapted to perform the following operations: based on the obtained configuration information, transmit a radio frequency signal during a first time period, or receive at least one radio signal reflected from at least one wireless tag 301, 302, 303 using the transmitted radio frequency signal during the first time period.

[0088] In some embodiments, the obtained configuration information may indicate that APs 110, 111, 112 are to transmit a radio frequency signal during the first time period. Alternatively, the obtained configuration information may indicate that APs 110, 111, 112 are to receive at least one radio signal reflected from at least one wireless tag 301, 302, 303 using the transmitted radio frequency signal during the first time period.

[0089] In some embodiments, when APs 110, 111, 112 are to receive at least one reflected radio signal during the first time period, APs 110, 111, 112 or processing circuitry 1010 may be adapted to perform the following operations, or may include a synchronization module 1013 adapted to perform the following operations: synchronize its uplink (UL) time period with one or more APs 110, 111, 112 in the wireless communication network 100 that are also configured to receive at least one reflected radio signal during the first time period. Further, when APs 110, 111, 112 are to receive at least one reflected radio signal during the first time period, APs 110, 111, 112 or processing circuitry 1010 may be adapted to perform the following operations, or may include an allocation module 1014 adapted to perform the following operations: allocate two frequency resource subsets (e.g., f - Δf n and f + Δf n ) within a determined set of frequency resources (e.g., ΔF) during the first time period to at least one wireless tag 301, 302, 303. In this case, according to some embodiments, APs 110, 111, 112 or processing circuitry 1010 may be adapted to perform the following operations, or may include a receiving module 1011 adapted to perform the following operations: receive at least one radio signal reflected from at least one wireless tag 301, 302, 303 in at least one of the two allocated frequency resource subsets (e.g., f - Δf n and f + Δf n ) during the first time period.

[0090] In some embodiments, when APs 110, 111, 112 are to transmit radio frequency signals during a first time period, the APs 110, 111, 112 or the processing circuit 1010 may be adapted to perform the following operations, or may include a synchronization module 1013 adapted to perform the following operations: synchronize its downlink (DL) time period with one or more APs 110, 111, 112 in the wireless communication network 100 that are also configured to transmit radio frequency signals during the first time period. Further, when APs 110, 111, 112 are to transmit radio frequency signals during a first time period, the APs 110, 111, 112 or the processing circuit 1010 may be adapted to perform the following operations, or may include a transmission module 1012 adapted to perform the following operations: send a scheduling grant to at least one of the wireless tags 301, 302, 303 during a second time period prior to the first time period, the scheduling grant indicating that the radio frequency signal is expected during the first time period. Further, when APs 110, 111, 112 are to transmit radio frequency signals during a first time period, the APs 110, 111, 112 or the processing circuit 1010 may be adapted to perform the following operations, or may include a transmission module 1012 adapted to perform the following operations: avoid transmitting during the first time period on a subset of the frequency resources allocated to at least one of the wireless tags 301, 302, 303 (e.g., f - Δf n and f + Δf n ).

[0091] In some embodiments, the APs 110, 111, 112 or the processing circuit 1010 may be adapted to perform the following operations, or may include a configuration module 1015 adapted to perform the following operations: configure at least one of the wireless tags 301, 302, 303 to reflect radio signals by shifting the transmitted radio frequency signal according to a respectively allocated frequency shift (e.g., Δf n ).

[0092] Further, the embodiments described above for implementing access to at least one of the wireless tags 301, 302, 303 in the wireless communication network 100 may be implemented by one or more processing circuits (such as, for example Figure 10The processing circuits 1010 in the APs 110, 111, 112 depicted in [description] and computer program code for performing the functions and actions of the embodiments herein. The above-mentioned program code can also be provided as a computer program product, for example, in the form of a data carrier carrying the computer program code, or in the form of a code device for performing the embodiments herein when loaded into the processing circuit 1010 in the APs 110, 111, 112. The computer program code can be provided, for example, as pure program code in the APs 110, 111, 112 or on a server and downloaded to the APs 110, 111, 112. Therefore, it should be noted that in some embodiments, the modules of the APs 110, 111, 112 can be implemented as computer programs stored in a memory, such as the memory module in [memory location], for execution by a processing circuit or processing module of the processing circuit 1010, such as [processor name]. Figure 10 in a memory module in [memory location] for execution by a processing circuit or processing module of the processing circuit 1010, such as [processor name]. Figure 10 of the processing circuit 1010.

[0093] Those skilled in the art will also understand that the processing circuit 1010 and the memory 102 described above can refer to a combination of analog and digital circuits, and / or one or more processors configured with software and / or firmware stored in the memory, which, when executed by one or more processors such as the processing circuit 1010, perform as described above. One or more of these processors and other digital hardware can be included in a single application-specific integrated circuit (ASIC), or several processors and various digital hardware can be distributed in several separate components, whether individually packaged or assembled into a system-on-chip (SoC).

[0094] The description of the example embodiments provided herein has been presented for purposes of illustration. The description is not intended to be exhaustive or to limit the example embodiments to the precise forms disclosed, and modifications and variations are possible in light of the above teachings, or can be obtained from various alternative practices of the provided embodiments. The example embodiments discussed herein are selected and described to explain the principles and nature of the various example embodiments and their practical applications, so that those skilled in the art can utilize the example embodiments in various ways and with various modifications suitable for the particular use intended. The features of the embodiments described herein can be combined in all possible combinations of methods, devices, modules, systems, and computer program products. It should be understood that the example embodiments presented herein can be implemented in any combination with each other.

[0095] It should be noted that the word "comprising" does not exclude the presence of other elements or steps than those listed, and the word "a" or "the" preceding an element does not exclude the presence of a plurality of such elements. It should also be noted that any figure signs do not limit the scope of the claims, that exemplary embodiments may be implemented at least in part by means of both hardware and software, and that several "means", "units" or "devices" may be represented by the same hardware product.

[0096] It should also be noted that the various example embodiments described herein are described in the general context of method steps or processes, which, in one aspect, can be implemented by a computer program product embodied in a computer-readable medium, comprising computer-executable instructions, such as program code, that are executed by a computer in a networked environment. Computer-readable media can include removable and non-removable storage devices, including but not limited to read-only memory (ROM), random access memory (RAM), compact discs (CDs), digital versatile discs (DVDs), and the like. Generally, program modules can include routines, programs, objects, components, data structures, and the like that perform specific tasks or implement specific abstract data types. Computer-executable instructions, associated data structures, and program modules represent examples of program code for executing the steps of the methods disclosed herein. A particular sequence of such executable instructions or associated data structures represents an example of corresponding actions for implementing the functions described in such steps or processes.

[0097] The embodiments herein are not limited to the preferred embodiments described above. Various replacements, modifications, and equivalents may be used. Therefore, the above embodiments should not be interpreted as limiting.

[0098] abbreviation

[0099] IoT: Internet of Things

[0100] AP: Access Point

[0101] DL: Downlink

[0102] UL: Uplink

[0103] RF: Radio Frequency

[0104] RFID: Radio Frequency Identification

[0105] BAP: Battery Assisted Passive

Claims

1. A method for implementing access to multiple wireless tags in a wireless communication network, which is performed by a network control entity, wherein, The wireless communication network includes two or more access points APs, and the method includes: The frequency shift (Δf n ) are respectively assigned to each wireless tag from the plurality of wireless tags, wherein the assigned frequency shift (Δf n ) to be used by at least two wireless tags from the plurality of wireless tags when reflecting a second radio signal using the transmitted first radio frequency signal; Configuring at least one first AP to transmit a radio frequency signal during a first time period; and Configuring at least one second AP to receive at least one radio signal reflected from the at least two wireless tags using the transmitted radio frequency signal during the first time period; Wherein, the configuration further includes: configuring the at least one second AP to allocate two subsets of frequency resources (f - Δf n , f + Δf n ) within a determined set of frequency resources (ΔF) during the first time period to the at least two wireless tags; Configure the at least one second AP to receive, during the first time period, the at least one radio signal reflected from the at least two wireless tags in at least one of two allocated frequency resource subsets (f - Δf n , f + Δf n ). Wherein, the configuration further includes: configuring the at least one first AP to avoid transmitting on the subset of frequency resources (f - Δf n , f + Δf n ) assigned to the at least two wireless tags during the first time period.

2. The method according to claim 1, wherein The configuration further includes: Configuring the at least one first AP to send a scheduling permission to the at least two wireless tags during a second time period before the first time period, the scheduling permission indicating that the transmitted radio frequency signal is expected during the first time period.

3. The method according to claim 1, further including: Configure one or more APs to configure the at least two wireless tags to reflect radio signals by shifting the transmitted radio frequency signals according to the respectively assigned frequency shifts (Δf n ).

4. The method according to any one of claims 1 to 2, further including: Determining that the at least one first AP is to transmit a radio frequency signal during a first time period, and that at least one second AP is to receive at least one radio signal reflected from at least two wireless tags using the transmitted radio frequency signal during the first time period.

5. The method according to claim 4, wherein, The determination further includes: Grouping each of the at least one first APs into a transmission TX group, wherein each of the at least one first APs in the TX group synchronizes their downlink DL time periods and transmits their radio frequency signals simultaneously; and Grouping each of the at least one second APs into a receiving RX group, wherein each of the at least one second APs in the RX group synchronizes their uplink UL time periods and receives the reflected radio signals from the at least two wireless tags simultaneously.

6. The method according to claim 1, wherein The network control entity is included in one or more of the APs, or forms a part of one or more of the APs, or is a separate network unit in the wireless communication network, or is provided as a service by a remote data processing network.

7. The method according to any one of claims 1 to 2, wherein The at least two wireless tags are semi-passive devices or passive devices powered by the transmitted radio frequency signal.

8. A network control entity for implementing access to multiple wireless tags in a wireless communication network, wherein, The wireless communication network includes two or more access points APs, wherein the network control entity is adapted to: Assign a frequency shift (Δf n ) to each of the plurality of wireless tags, wherein the assigned frequency shift (Δf n ) will be used by at least two of the plurality of wireless tags when reflecting a second radio signal using the transmitted first radio signal; Configure at least one first AP to transmit a radio frequency signal during a first time period, and configure at least one second AP to receive at least one radio signal reflected from the at least two wireless tags using the transmitted radio frequency signal during the first time period; Wherein, in order to configure the at least one second AP (110, 111, 112) to receive, the network control entity is further adapted to: configure the at least one second AP to allocate two frequency resource subsets (f - Δf n , f + Δf n ) within a determined frequency resource set (ΔF) to the at least two wireless tags during the first time period; Configure the at least one second AP to receive, during the first time period, the at least one second radio signal reflected from the at least two wireless tags in at least one of the two allocated frequency resource subsets (f - Δf n , f + Δf n ); and Configure the at least one first AP to avoid transmitting on the subset of frequency resources (f - Δf n , f + Δf n ) allocated to the at least two wireless tags during the first time period.

9. The network control entity according to claim 8, further adapted to: Configure the at least one first AP to send a scheduling permission to the at least one wireless tag during a second time period before the first time period, the scheduling permission indicating that the transmitted radio frequency signal is expected during the first time period.

10. The network control entity according to claim 8, further adapted to: Configure one or more of the at least one first and / or second AP to configure the at least two wireless tags to reflect radio signals by shifting the transmitted radio frequency signals according to respectively assigned frequency shifts (Δf n ).

11. The network control entity according to claim 8, further adapted to: Determine that the at least one first AP is to transmit a radio frequency signal during a first time period, and that at least one second AP is to receive at least one radio signal reflected from at least one wireless tag using the transmitted radio frequency signal during the first time period.

12. The network control entity according to claim 11 is further adapted to: Group each of at least one first AP into a transmission TX group, where Each of at least one first AP in the TX group synchronizes its downlink DL time period and transmits its radio frequency signal simultaneously; And Group each of the at least one second AP into a receiving RX group, wherein each of the at least one second AP in the RX group synchronizes its uplink UL time period and receives the reflected radio signals from the at least two wireless tags simultaneously.

13. The network control entity according to claim 8, comprising at least one processing circuit and a memory, wherein, The memory contains instructions executable by the at least one processing circuit.

14. A method for implementing access to multiple wireless tags in a wireless communication network, performed by a system including at least two access points AP, the method comprising: Obtaining configuration information by the at least two APs from a network control entity or from pre-configured parameters; Based on obtaining the configuration information, the method further includes: Configure at least two of the plurality of wireless tags to reflect radio signals by shifting transmitted radio frequency signals according to respectively assigned frequency shifts (Δf n ); Synchronizing, by a first AP among the at least two APs, the downlink DL time period of the first AP with one or more APs in the wireless communication network that are also configured to transmit radio frequency signals within a first time period; Sending, by the first AP among the at least two APs, a scheduling permission to the at least two wireless tags within a second time period before the first time period, the scheduling permission indicating that a radio frequency signal is expected within the first time period; Based on the obtained configuration information, transmitting, by the first AP among the at least two APs, a radio frequency signal within the first time period; At least one second AP among the at least two APs allocates two frequency resource subsets (f - Δf n , f + Δf n ) within the determined frequency resource set (ΔF) to the at least one wireless tag during the first time period; The first AP among the at least two APs avoids transmitting during the first time period on a subset of frequency resources (f - Δf n , f + Δf n ) allocated to the at least two wireless tags; and The second AP among the at least two APs receives, during the first time period, at least one second radio signal reflected from at least two wireless tags (301, 302, 303) using the transmitted radio frequency signal in at least one of the two allocated frequency resource subsets (f - Δf n , f + Δf n ).

15. The method according to claim 14, wherein, The obtained configuration information indicates that the first AP is to transmit a radio frequency signal within a first time period, or the second AP is to receive the at least one radio signal reflected from at least one wireless tag using the transmitted radio frequency signal within the first time period.

16. The method according to claim 14 further includes: When the AP is to receive at least one reflected radio signal within the first time period, Synchronizing, by a second AP among the at least two APs, the uplink UL time period of the AP with one or more APs in the wireless communication network that are also configured to receive at least one reflected radio signal within the first time period.

17. A wireless communication network includes at least two access points AP for implementing access to a plurality of wireless tags in the wireless communication network, wherein, The at least two APs in the wireless communication network are adapted to: Obtain configuration information from a network control entity or from pre-configured parameters; Based on obtaining the configuration information, the AP is further adapted to: Configure at least two of the plurality of wireless tags to reflect radio signals by shifting the transmitted radio frequency signals according to respectively assigned frequency shifts (Δf n ); Transmit a first radio frequency signal at a frequency f within a first time period; And During the first time period, two subsets of frequency resources (f - Δf n , f + Δf n ) within the determined set of frequency resources (ΔF) are allocated to the at least two wireless tags; and Receive at least one second radio signal reflected from the at least two wireless tags using the transmitted radio frequency signal in at least one of two allocated subsets of frequency resources (f - Δf n , f + Δf n ) during the first time period.

18. The wireless communication network according to claim 17, comprising at least one processing circuit and a memory, wherein, The memory contains instructions executable by the at least one processing circuit.

19. A computer-readable storage medium, on which a computer program is stored, the computer program including computer-readable instructions that, when executed by a processor, cause the processor to execute the method according to any one of claims 1 to 7 and 14 to 16.

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