CDMA-IA NETWORK CONCEPT OF OPERATIONS AND MEDIUM ACCESS CONTROL (MAC) LAYER.

Abstract

This disclosure describes the operating concept and medium access control protocols of a wireless communication system that uses Code Division Multiple Access with Interference Avoidance (CDMA-IA) as its physical layer. The system can dynamically share a common band with other networks without a central radio resource controller. In one embodiment, the wireless communication system includes several radio nodes forming a wireless mesh network, where pairs of radio nodes use individually optimized time-division duplexing. At least one radio node includes a software-defined radio, memory, and an electronic processor. The electronic processor is configured to control the software-defined radio to transmit a pilot signal and share various status information with the other nodes in the network.The shared information includes local spectrum usage and node connectivity sets. The dominant sharing of spectrum usage among all nodes allows for maximizing the use of the shared band.

Description

CDMA-IA NETWORK CONCEPT OF OPERATIONS AND MEDIUM ACCESS CONTROL (MAC) LAYER Cross-reference to related application

[0001] This application claims the benefit of United States Provisional Application No. 62 / 979.141, filed on February 20, 2020, the full contents of which are incorporated herein by reference. FIELD OF INVENTION

[0002] This disclosure relates generally to wireless communication systems. More specifically, this disclosure relates to a wireless communication system with code division multiple access and interference avoidance (CDMA-IA communication system). BACKGROUND OF THE INVENTION

[0003] Conventional CDMA methods accept some interference from other users and generate interference for others, although it is relatively small relative to the processing gain. In some applications, the superior manual interference reduction with conventional propagation spectrum processing may be insufficient for SNIR requirements. SUMMARY OF THE INVENTION

[0004] The concept of CDMA with interference avoidance (CDMA-IA) was introduced as a novel water-fill physical layer technique suitable for mesh networks. For reference, the CDMA-IA physical layer is defined by Churan, G., Wireless Communication Systems with Code-Division Multiple Access and Interference Avoidance, U.S. Patent No. 10,666,316 and by Gary Churan, Santanu Dutta, and Dunmin Zheng, Dynamic spectrum sharing with other networks using optimized PHY / MAC layers, Winnforum Summit, San Diego, October 23, 2019.<https: / / www.wirelessinnovation.org / assets / Proceedings / 2019 / TSl.2%20Dutta%20Presentation.pdf > .

[0005] CDMA-IA automatically adjusts its spectrum usage to fit into gaps in the ambient spectrum of other networks, as observed at a receiving terminal, providing certain advantages compared to traditional CDMA. The most important advantage is the minimization of interference caused to and from other networks.

[0006] There are several practical applications for this CDMA-IA concept, including the 3.5 GHz Citizens Band Radio System (CBRS) and traditional high-frequency communications. In CBRS, General Authorized Access (GAA) device types are well-suited to use CDMA-IA because they occupy the lowest position in the CBRS spectrum-sharing hierarchy—they must not interfere with higher-priority receivers and operate using unused spectrum from higher-priority systems. Although an adequate supply of this spectrum is expected, spectrum allocation is expected to be dynamic to meet the evolving needs of higher-priority military users. This requires that the lower communication protocol layers of GAA systems be similarly dynamic in their use of available spectrum.

[0007] This disclosure, and in particular the implementations set forth below, expands upon the previously described CDMA-IA physical layer and describes a new medium access control (MAC) layer. Furthermore, new concepts of operation (CONOPS) are described herein, which are appropriate for mesh networks that can adapt to changing traffic patterns and environmental conditions.

[0008] In one embodiment, the disclosure includes a wireless communication system comprising several radio nodes forming a wireless mesh network, and pairs of the several radio nodes are configured to communicate with each other. At least one of the radio nodes includes a software-defined radio, a memory, and an electronic processor communicatively connected to the memory.The electronic processor is configured to control the software-defined radio and transmit a pilot signal and initial status information from at least one radio node to other radio nodes of the various radio nodes that are part of the wireless mesh network, control the software-defined radio to gather pilot signals and initial status information from the other radio nodes that are part of the wireless mesh network, control the software-defined radio to transmit an access request to one of the other radio nodes, and control the software-defined radio to initiate the exchange of traffic data with one of the other radio nodes in response to receiving an access grant from one of the other radio nodes.

[0009] In another embodiment, the disclosure includes a wireless communication method. The method includes controlling, with an electronic processor, a software-defined radio to transmit a pilot signal and first status information from at least one radio node of several radio nodes to other radio nodes of the several radio nodes that are part of a wireless mesh network. The method includes controlling, with the electronic processor, the software-defined radio to gather pilot signals and second status information from the other radio nodes of the several radio nodes that are part of the wireless mesh network. The method includes controlling, with the electronic processor, the software-defined radio to transmit an access request to one of the other radio nodes.The procedure also includes control, with the electronic processor, of the software-defined radio to initiate the exchange of traffic data with one of the other radio nodes in response to receiving an access grant from one of the other radio nodes.

[0010] In another embodiment, the disclosure includes a non-transient, computer-readable medium comprising instructions that, when executed by a server, cause the server to perform a set of operations. The set of operations includes controlling a software-defined radio to transmit a pilot signal and first status information from at least one radio node of several radio nodes to other radio nodes of the several radio nodes that are part of a wireless mesh network. The set of operations includes controlling the software-defined radio to gather pilot signals and second status information from the other radio nodes of the several radio nodes that are part of the wireless mesh network. The set of operations includes controlling the software-defined radio to transmit an access request to one of the other radio nodes.The set of operations also includes software-defined radio control to initiate traffic data exchange with one of the other radio nodes in response to receiving an access grant from one of the other radio nodes. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] FIG. 1 and 2 are diagrams illustrating a CDMA-IA network adapting from a first CDMA-IA network spectrum usage observed in a first geographical location to a second CDMA-IA network spectrum usage observed in a second different geographical location, in accordance with various aspects of the disclosure.

[0012] FIG. 3 is a block diagram illustrating an example of a radio node architecture, in accordance with various aspects of the disclosure.

[0013] FIG. 4 is a diagram that illustrates an example of plot structure, in accordance with various aspects of disclosure.

[0014] FIG. 5 is a diagram that illustrates an example of a network between several nodes, in accordance with some aspects of the disclosure.

[0015] FIG. 6 is a table illustrating an example of a Connectivity Matrix, in accordance with various aspects of the disclosure.

[0016] FIG. 7 is a transaction ladder diagram that illustrates an example of establishing a communication link between a UE-m and a UE-n, in accordance with various aspects of this disclosure.

[0017] FIG. 8 is a flowchart illustrating a wireless communication procedure, in accordance with some aspects of the disclosure. DETAILED DESCRIPTION OF THE EXAMPLE PRODUCTIONS

[0018] Before the embodiments of this disclosure are explained in detail, it should be understood that this disclosure is not limited in its application to the details of interpretation and arrangement of the components set forth in the following description or illustrated in the following drawings. This disclosure may take other embodiments or may be carried out or implemented in various ways.

[0019] Figures 1 and 2 are diagrams illustrating a CDMA-IA 10 network that scales from a first CDMA-IA 100 network spectrum usage observed at a first geographic location (e.g., node-i) to a second CDMA-IA 200 network spectrum usage observed at a different second geographic location (e.g., node-j), in accordance with various aspects of the disclosure. In both cases, a common 10 MHz bandwidth is shared between a CDMA-IA network and several networks, such as Network #1, Network #2, and Network #3.

[0020] In the example in FIG. 1, the first CDMA-IA 100 network spectrum usage, observed at a first i-node receiving location, has four occupied CDMA-IA spectrum sub-bands 102-108 and three occupied sub-bands 110-114 from another network (referred to as the Network). According to the CDMA-IA physical layer design described previously, the CDMA-IA network automatically detects spectral gaps, or holes, in the spectrum of the signals received at each CDMA-IA receiver. All CDMA-IA transmit signals, except broadcast signals, constrain their spectrum usage to fit into the interference holes of another network at the destination CDMA-IA receiver location.

[0021] FIG. 2 shows an example of interference spectrum from another network, at the second node-j receive location. As illustrated in the diagram, the CDMA-IA signals targeting the second receive location, specifically sub-bands 102, 202, and 204, adjust their spectrum usage to fit into the gaps left by the spectra of Network #1 110, Network #3 114, and Network #5 206.

[0022] Figure 3 is a block diagram illustrating an example of a radio node architecture 300, in accordance with various aspects of the disclosure. Other architectures can also deliver the same functionality and are equally covered by the functionality described herein. In the example in Figure 3, the radio node architecture 300 includes a server 302, which is communicatively and bidirectionally coupled to a software-defined radio (SDR) 304, connected to a transmit / receive antenna array 306. As illustrated in Figure 3,3, the server 302 includes a memory 308, a traffic data channel processor 310, a broadcast and control channel processor 312, a spectrum detection processor 314, a spectral usability mask processor 316, a propagation spectral pilot channel processor 318, an intelligent controller 320, an input / output application data processor 322, and a communication bus 324.

[0023] SDR 304 performs frequency translation between the complex baseband signal at the server interface and the analog RF signal at the antenna interface. The complex baseband signals (digital I and Q) are generated by server 302, which may comprise a combination of digital signal processors (DSPs), general-purpose processing units (GPUs), and application-specific integrated circuits (ASICs), along with program and data memory resources 308. Generally, the data memory, used for temporary data storage, is transient, and the program memory, used to store instructions executed by server 302, is non-transient. The focus of this description is on the functional architecture of server 302.The processors that comprise the overall functionality of Server 302 are implemented in software using the hardware resources (processor and memory) available on Server 302. In other words, a processor is a functional element that executes the specified process. The process can be implemented using a combination of hardware and software enabling means, including entirely in software on a general-purpose electronic processor, or server, without exceeding the scope of this disclosure. The functional architecture is described later.

[0024] An input / output application data processor 322 performs formatting functions on input and output data, which is typically presented at the interface as IP or UDP packets. A traffic data channel processor 310 executes the media access control (MAC) and physical layer processes of the chosen communication protocol stack for transmission and reception; the physical and MAC layer processes are illustrated as processes 326 and 328, respectively. A broadcast and control channel processor 312 generates and receives broadcast and control channel data. Like the traffic data channel processor 310, the broadcast and control channel processor 312 also includes a physical layer process 330 and a MAC layer process 332.A propagation spectral pilot channel processor 318 generates the pilot channel used for time and frequency synchronization of the transmitted signal at the destination receiver; a spectral detection processor 314 estimates the spectral usage of the wireless broadband channel. A spectral usability mask processor 316 generates a usability mask from the spectral usage detected by the spectral detection processor 314.

[0025] In some embodiments, the radio node 300 architecture may include fewer components or additional components in configurations different from that illustrated in FIG. 3. In addition, the radio node 300 architecture may carry out functionality in addition to the functionality described herein.

[0026] This disclosure focuses on the MAC layer and the concept of operations (CONOPS) at a system level, e.g., MAC layer processes 328 and 332 as previously described. One of the main attributes of any MAC layer is transmit / receive duplexing. In particular, adaptive time-division duplexing (TDD) is described herein, as TDD maximizes spectral efficiency in a dynamic environment. CONOPS is highly dependent on the choice of network topology, the main choices being hub and distribution (as in a traditional cellular network) and ad hoc mesh (e.g., Bluetooth, where there is no mandatory central repeater node, also known as a base station, for exchanging packets between network nodes). The decentralized nature of a mesh network allows for maximizing spectral efficiency across the network in dynamic spectral sharing.

[0027] The intersection of the physical layer attributes of CDMA-IA (i.e., physical layer processes 326 and 330) and those of TDD duplexing and mesh topology creates some unusual system design challenges. With CDMA as the multiple access technique, one terminal can exchange packets simultaneously with several terminals in parallel. However, with TDD, a terminal cannot transmit and receive at the same time. Furthermore, a common uplink phase (i.e., time-synchronized) and a common downlink phase for all terminals in the network cannot be used because the network topology is a mesh type, which is not the case in core and distribution cellular networks where common phases can be used.

[0028] The potential presence of hidden nodes in the network enables the reuse of TDD time slots for a given frequency without interference, thus maximizing spectral efficiency, similar to frequency reuse in a traditional cellular network. In this context, 'hidden nodes' refers to nodes that cannot communicate directly. For example, if all terminals are within range of each other, a relatively simple TDD scheme, or TD_Map, can be used, where each terminal has a reserved, repeated opportunity to transmit. The other terminals would be in receive mode during this time.However, this static scheme will not be very spectrally efficient in a dynamic environment where the following situations are likely to occur: 1) the traffic load on the terminals is dynamic and non-uniform, 2) the terminals need to transmit broadcast channels (including pilot signals and spectral usability masks), which require maximizing airtime, and 3) not all terminals will be within connection range (some may be hidden), making it spectrally wasteful to allocate unique transmission epochs across the network for each terminal.

[0029] The chosen duplexing scheme is adaptive TDD, where the transmit / receive duplexing time map (TD_Map) of each terminal is unique and depends on its operating environment and workload. Communication between a given pair of terminals must be consistent with the TD_Map of both. In the present system, the TD_Map for each terminal is negotiated adaptively between terminals that are within communication range and need to communicate. Transmission times are reused between terminals that are not within connection range or do not need to communicate.

[0030] Frame structure

[0031] The time domain is divided into hierarchical frames of fixed durations, and a certain number (e.g., N) of frames may form a superframe. Frame time is synchronized with GPS or another universal time source. FIG. 4 is a diagram illustrating an example 400 frame structure, in accordance with various aspects of the disclosure.

[0032] Frame numbering is applied throughout the network, where the term network refers to a common geography. Between unconnected regions with poor mutual radio propagation, all frames can be reused.

[0033] Each frame begins with a relatively short, reserved listening period 402 for spectral detection. Transmission is not permitted by any terminal, or user equipment (DE, which is also synonymous with radio node as described herein), of the CDMA-IA network during listening period 402, which consists of a radio silence period for the entire network. However, spectral detection can and should occur during all other receive time slots for each UE. This is because the receive energy spectral densities of CDMA-IA signals are expected to be low enough to be easily distinguishable from signals from other networks (which are assumed not to be CDMA). In other words, the identification of spectral holes in the ambient spectrum should not be materially affected by transmissions within the CDMA-IA network.The intelligence in the terminal will be able to make this determination.

[0034] Each frame also has a reserved receive slot 404 for receiving dedicated control information (control information with the target of a particular UE). For each UE, slot 404 occurs at a unique (time-orthogonal) instant in each frame across the superframe, and then repeats in each superframe. Each UE in the network is assigned to one of these 404 slots in a superframe. The number of frames in a superframe must therefore be at least equal to the number of UEs in a connected group, as will be discussed in detail later.

[0035] This reserved receive slot 404 is designated as the incoming dedicated control channel. Any number of UEs may use this slot 404 to communicate network control information to the receiving UE, such as access requests, access grants, and other network control information. These communications are unicast (one-to-one), and as such are also called dedicated control signals; the logical channel is called the dedicated control channel. Because the dedicated control signals are targeted at a specific UE, they use a partial-band physical layer (band not fully occupied), matched to the spectral usage of the destination UE, in accordance with the CDMA-IA specifications.

[0036] Unreserved time in a frame is divided into the following channels: 1) dedicated traffic channels and transmission control channels and 2) broadcast channels.

[0037] Dedicated traffic channels and transmission control channels

[0038] Traffic channels can be either transmit or receive. Currently, only unicast traffic is supported. Furthermore, unreserved time is determined through negotiation between UEs in a connected group.

[0039] Each UE negotiates bilaterally with other UEs to determine a time duplexing plan, or map (TD_Map), that works for the UE and every UE that needs to communicate with the UE (a member of the connected group). It is important to note that slot allocations can be made for future frames, beyond the frame immediately following. The lifetime of a TD_Map is finite, although its lifetime can be configured for a specific network or made dependent on traffic trends, such as network load and interference. Once the lifetime of a TD_Map expires, the UE renegotiates a new TD_Map. The negotiation of the next TD_Map can occur in the background during the current TD_Map.

[0040] No specific negotiation plans are proposed in this document. However, it is understood that this plan is the decentralized equivalent of the pre-existing Radio Access Network (RAN) programming.

[0041] In determining which TD_Map will operate in each case, each UE ensures that a minimum fraction is enabled for two types of broadcast transmission channels: the broadcast control channel and the broadcast pilot signal. This enablement can opportunistically utilize all non-receive epochs in the TrDCCH_TD_Map (see FIG. 1). Broadcast transmission channels are also referred to as opportunistic control channels (OCCHs) because they are scheduled opportunistically, subject to the requirements of the reserved control channel (R.CCH) and the dedicated traffic control channel (TrDCCH).

[0042] Broadcast channels

[0043] The following broadcast channels have support: (1) broadcast control channel, and (2) broadcast pilot signal.

[0044] Broadcast control channel

[0045] The broadcast control channel carries information such as the spectral usability mask, which is a binary version of the interference spectrum at the UE location; the connectivity matrix, which defines the list of UEs that are within connection range from the UE; and the TD_Maps illustrated in FIG. 4.

[0046] The spectral usability mask at a given UE location is used by other UEs to spectrally shape the dedicated control and traffic signals sent to that particular UE. This spectral shaping cannot be carried out for broadcast signals since these signals are not intended for a UE at a particular location. Therefore, full-band CDMA-IA signals are used for broadcast signals, while part-band and spectrally shaped signals are used for dedicated control and traffic channel signals.

[0047] The connectivity matrix shows the UE's connectivity with other UEs in the network. The TD_Maps (RCCH_TD_Map, OCCH_TD_Map, and TrDCCH_TD_Map) show the current organization of TDD channels negotiated in the UE. A new UE attempting to establish a link with this UE must follow this map or propose a new organization.

[0048] Broadcast pilot signal

[0049] The broadcast pilot signal communicates time and frequency references used to demodulate signals received from the transmitting UE. The pilot signal is unique to the UE and identifies the UE. In addition to communicating the time / frequency references, the pilot signal may carry low-data-rate, essential control information, similar to the 50-bit-per-second (bps) ephemeris / almanac data in GPS. An example of such data is the CDMA-IA codeset ID. The association between the codeset and the UE can be absolute or ad hoc, as described below.

[0050] In an example of absolute association, the mapping of the code set (e.g., a pseudo-noise (PN) set or other codes) to the UE can be absolute, i.e., related to the UE's electronic serial number, which is used to create a long PN code that is unique to the UE. All UEs are aware of this sequence at any given time based on a specified long code mask that relates to a particular UE. This procedure can generate PN codes to accommodate any number of UEs.

[0051] In an ad hoc association example, the size of the code library is limited. A UE selects a particular codeset ID for itself, based on the number of codesets already in use within a given listening range. UEs would select the codeset on their own and use a temporary electronic ID, related to the codeset, to identify themselves to other UEs; this ID can change in the next session. There is no permanent association between the physical UE, as identified by its electronic serial number, and the codeset.

[0052] Network connectivity

[0053] Figure 5 is a diagram illustrating an example of a 500 network among several nodes, in accordance with some aspects of the disclosure. The 500 network is designed as a mesh network in which there is connectivity between groups of UEs, called connected groups, which are subsets of the global set of all UEs.

[0054] As illustrated in FIG. 5, the network includes three connected groups 502, 504, and 506. Connected group 502 includes UE 1, 2, 3, and 4. Connected group 504 includes UE 3, 4, 5, and 6. Connected group 506 includes UE 4, 6, 7, 8, and 9.

[0055] Links between UEs that are not directly connected can be established using repeater nodes. In the example in FIG. 5, UEs 4, 5, and 6 are repeater nodes. Also in the example in FIG. 5, UEs 1, 3, 7, and 8 are hidden nodes.

[0056] Each of the repeater links is independent at the physical layer (involving demodulation and remodulation at the repeater). This independence at the physical layer avoids the need to share the spectral usability mask and G matrices between hidden nodes.

[0057] The UEs determine the opportunities for repeat transport from the connectivity matrices broadcast by each UE through the broadcast control channel. FIG. 6 consists of a table illustrating an example of a 600 connectivity matrix, in accordance with some aspects of the disclosure.

[0058] The connectivity matrix 600 is arranged in a grid, with the transmitting UE indices as row headings and the receiving UE indices as column headings. The entries in the Qtx,rx table indicate the signal quality of the transmitting UE's (Tx) broadcast control signal as measured at the receiving UE (Rx), for example, ranging from 0 (unusable), 1 (weak), 2 (acceptable), to 3 (good). At 2 bits per entry, the total field size is 2K(K-1) data bits, where K is the number of active UEs. Because the link may not be reciprocal due to different environmental conditions at the two receivers (for example, interference and multipath), the connectivity matrix 600 may not be diagonally symmetric. An appropriate metric for Qtx,rx may be the noise-to-interference ratio (SNIR) at the receiver.The channel quality indicator Qtx,rx can be used to determine the coding and modulation scheme of the transmitted signal, and whether the link between the two UEs can be considered acceptable, for example, 2: acceptable or 3: good. The signal quality must be acceptable in both directions for the link to be considered bidirectionally closed, which is generally a requirement for unicast and link protocols.

[0059] It is important to note that, to implement the transport repeater, each UE will need to rebroadcast the connectivity matrices received from other UEs (not just transmit its own connectivity information). The deeper the level of connectivity that is rebroadcast, the greater the number of repeater hops that the 500 network can support. It should also be clarified that, in a congested network, the link signal quality may depend not only on the distance between two nodes but also on spectral utilization, local noise, and multipath conditions at the receiver. Therefore, a longer repeater path that uses less congested repeater nodes may actually offer better link quality than a shorter one.Due to the ability of the CDMA-IA network to monitor Qtx,rx on each link, the distributed intelligence in the system allows for optimal routing of repeater paths using various network performance criteria.

[0060] Network setup and disconnection

[0061] FIG. 7 is a transaction ladder diagram illustrating an example 700 of establishing a link between an m-UE and an n-UE, in accordance with various aspects of this disclosure. In transaction 702, the m-UE wakes up. In transaction 704, after waking up, the m-UE gathers pilot signals and status information about the UEs within connectivity range. During transaction 704, the m-UE gathers the pilot signal and status information from the n-UE.

[0062] In transactions 706 and 708, the UE-m also initiates the broadcasting of the UE-m's own pilot signal and status information (the spectral usability mask, the connectivity matrix, the TD_Maps as previously described).

[0063] In transaction 710, the UE-m waits a certain period for its status information to be filtered out onto the network. In transaction 712, the UE-n receives the pilot and status information from the UE-m transmitted in transaction 710. In transaction 714, the UE-m wants to exchange data with the UE-n, which is within listening range, and the UE-m sends an Access_Request message on the UE-n's dedicated ingress control channel.

[0064] The dedicated ingress control channel uses a partial-band PN or gold code signal, spectrally matched to the interference spectrum on UE-n. The Access_Request is sent in an ingress control protocol data unit (PDU) that is common across the network—it can be thought of as a RACH PDU shared by all UEs. The PDU uses a unique PN or gold code for each destination UE. UE-n listens to this channel in each RCCH time slot. This is a propagation spectral signal, and various RACH signals can be distinguished if the arrival times are longer than the chip duration.

[0065] The Access_Request signal is modulated with the transmitting UE ID (in this case, nrirznn / cznz / q / uli, the UE-m ID), allowing the receiving UE-n to identify the UE-m as the source of the access request. Time / frequency correction feedback is provided where appropriate, as is common practice in RACH signal processing.

[0066] In transaction 716, the UE-n processes the access request from UE-m. In transaction 718, the UE-n proposes a TrDCCH_TD_Map_l on a dedicated inbound control channel of UE-m. The UE-n is aware of the inbound DCCH of UE-m from the status information received from UE-m.

[0067] In transaction 720, the UE-m processes the UE-n's TrDCCH_TD_Map_1. The UE-m can exchange traffic data with the UE-n, starting with the next frame it follows, using the UE-n's existing TrDCCH_TD_Map. If the UE-m finds the UE-n's existing TD_Map unacceptable, in transaction 722, the UE-m can propose a different TrDCCH_TD_Map_2 using the UE-n's input DCCH, and this proposal can be implemented in a future frame specified by the UE-n.

[0068] In transaction 724, the UE-n processes the UE-m's TrDCCH_TD_Map_2. In transaction 726, the UE-n can respond to the UE-m's proposed TD_Map on its current outgoing DCCH or the UE-m's incoming DCCH, as illustrated in FIG. 7. The response can be an acceptance (i.e., an Access_Grant) of the UE-m's proposed TD_Map along with the future frame ID when it will take effect (FR_N). Alternatively, the UE-n can make a counterproposal with a frame ID. This negotiation process can continue for a finite number of cycles with an outgoing path.

[0069] In transaction 728, the UE-m processes the acceptance of the UE-n. In transaction 730, the UE-m initiates the exchange of traffic data with the UE-n based on the future frame (i.e., FR_N).

[0070] In view of the above, the UE-m joins a network (e.g., the 500 network) by initiating a search for all pilot signals on the network (e.g., GPS). The UE-m begins transmitting pilot signals in discontinuous bursts (in GPS, they are transmitted continuously). In some cases, the band may be partially congested, and an interference whitening filter will be needed (GPS does not use interference whitening).

[0071] Once sufficient samples of the pilot signal have been collected, the UEm can achieve time and frequency synchronization for each UE within its listening range (e.g., UE-n), i.e., within its connected group. The UE-m thus becomes aware of which UEs are within its listening range. The UE-m can also determine the CDMA-IA code set of each UE within its listening range. This information is embedded as modulated data in the pilot signals transmitted by the UEs, or established by association, based on the code used in the pilot signal. The UE-m can also receive the spectral usability map and connectivity matrix of each UE.

[0072] In addition, in some examples, a double-hop link can be configured. However, the link is not limited to a double hop, and the number of hops can be increased using the same approach; it should be noted that a higher number of hops requires deeper connectivity information to be shared between the UEs.

[0073] Configuring a multi-hop link

[0074] A double-hop link is configured by a transmitting UE (i.e., the UE-m) based on the connectivity matrix (e.g., the 600 connectivity matrix). For example, the connectivity matrix may show that a UE-m / UE-n / UE-k link can be closed based on the channel quality indicator Q of the two sublinks (mn) and (nk), but an end-to-end link (mk) cannot be closed.

[0075] The UE-m will inform the UE-n of the specifications of the second link (e.g., the UE-k ID, throughput, and QoS targets) during the resource negotiation phase. The end-to-end link will be configured if the negotiation is successful. The two links are also independent at the physical layer; that is, the operational G matrix on the second link is determined by UE-n and not UE-m.

[0076] The number of hops can increase beyond two if the same previously mentioned approach is followed; it should be noted that a greater number of hops will require sharing deeper connectivity information between UEs.

[0077] Figure 8 is a flowchart illustrating a wireless communication procedure 800, in accordance with some aspects of the disclosure. As illustrated in Figure 8, the 800 procedure includes controlling, with an electronic processor, a software-defined radio to transmit a pilot signal and first status information from at least one radio node of several radio nodes to other radio nodes of the several radio nodes that are part of a wireless mesh network (in block 802). The 800 method includes controlling, with the electronic processor, the software-defined radio to gather pilot signals and second status information from other radio nodes of the several radio nodes that are part of the wireless mesh network (in block 804).Procedure 800 includes the control, by the electronic processor, of the software-defined radio to transmit an access request to one of the other radio nodes (in block 806). Procedure 800 also includes the control, by the electronic processor, of the software-defined radio to initiate the exchange of traffic data with one of the other radio nodes in response to receiving an access grant from one of the other radio nodes (in block 808).

[0078] The following is a non-limiting set of listed examples of wireless communication systems, wireless communication networks, wireless communication procedures, and non-transient non-computer-readable media of this disclosure.

[0079] Example 1: A wireless communication system comprising: several radio nodes forming a wireless mesh network, wherein pairs of the several radio nodes are configured to communicate with each other, at least one radio node of the several radio nodes includes a software-defined radio, a memory, and an electronic processor communicatively connected to the memory, and the electronic processor is configured to control the software-defined radio to transmit a pilot signal and first status information from at least one radio node to other radio nodes of the several radio nodes that are part of the wireless mesh network, control the software-defined radio to gather pilot signals and second status information from the other radio nodes that are part of the wireless mesh network, control the software-defined radio to transmit an access request to one of the other radio nodes,and control the software-defined radio to initiate traffic data exchange with one of the other radio nodes in response to receiving an access grant from one of the other radio nodes.

[0080] Example 2: The wireless communication system of Example 1, wherein, in order to control the software-defined radio to transmit the access request to one of the other radio nodes, the electronic processor is further configured to determine an input dedicated control channel (DCCH) related to one of the other radio nodes from the first state information, and to control the software-defined radio to transmit the access request to one of the other radio nodes on the input DCCH related to one of the other radio nodes from the first state information.

[0081] Example 3: The wireless communication system of Examples 1 or 2, wherein the electronic processor is further configured to receive a proposed TD_Map from one of the other radio nodes in response to the transmission of the access request, determine whether the proposed TD_Map is acceptable, in response to the determination that the proposed TD_Map is not acceptable, generate a second proposed TD_Map that is acceptable, and control the software-defined radio to transmit the second proposed TD_Map to one of the other radio nodes, and wherein granting access is an acceptance of the second proposed TD_Map.

[0082] Example 4: The wireless communication system of Example 3, wherein the electronic processor is further configured to determine an input dedicated control channel (DCCH) related to one of the other radio nodes from the first status information, control the software-defined radio to receive the proposed TD_Map on the input DCCH related to one of the other radio nodes, control the software-defined radio to transmit the second proposed TD_Map on the input DCCH related to one of the other radio nodes, and control the software-defined radio to receive the access grant on the input DCCH related to one of the other radio nodes.

[0083] Example 5: the wireless communication system of any of Examples 1 to 4, wherein the second state information includes connectivity matrices of the other radio nodes.

[0084] Example 6: the wireless communication system of any of Examples 1 to 5, wherein the second status information includes TD_Maps of the other radio nodes.

[0085] Example 7: the wireless communication system of any of Examples 1 to 6, wherein the second state information includes spectral usability masks of the other radio nodes.

[0086] Example 8: the wireless communication system of any of Examples 1 to 7, wherein the first status information includes a connectivity matrix of at least one radio node.

[0087] Example 9: the wireless communication system of any of Examples 1 to 8, wherein the first status information includes a TD_Map of at least one radio node.

[0088] Example 10: the wireless communication system of any of Examples 1 to 9, wherein the first state information includes a spectral usability mask of at least one radio node.

[0089] Example 11: The wireless communication system of any of Examples 1 to 10, wherein the pairs of the various radio nodes are configured to communicate with each other and further include the pairs of the various radio nodes communicating indirectly with each other, using one or more additional radio nodes of the various radio nodes as repeaters, and wherein a repeater path is adaptively determined to maximize end-to-end network performance criteria, informed by a signal quality metric between the pairs of the various radio nodes.

[0090] Example 12: A wireless communication network comprising: several radio nodes using time-division duplexing with a first period during which a first radio node transmits and a second radio node receives, and a second period during which the second radio node transmits and the first radio node receives, wherein a ratio between the first and second periods varies over time.

[0091] Example 13: the wireless communication network of Example 12, wherein the adjustment of the ratio between the first and second period is made in response to interference and traffic conditions at the various radio nodes.

[0092] Example 14: the wireless communication network of Examples 12 or 13, wherein the various radio nodes include pairs of first and second radio nodes that communicate with each other simultaneously using the respective ratios of the respective first and second periods with more than one value.

[0093] Example 15: The wireless communication network of any of Examples 12 to 14, wherein the various radio nodes include first and second radio node pairs that communicate with each other simultaneously; each of these pairs uses a time duplexing map that is optimized for each pair.

[0094] Example 16: A wireless communication procedure comprising the following steps: controlling, with an electronic processor, a software-defined radio to transmit a pilot signal and first status information from at least one radio node of several radio nodes to other radio nodes of the several radio nodes that are part of the wireless mesh network; controlling, with the electronic processor, the software-defined radio to gather pilot signals and second status information from the other radio nodes of the several radio nodes that are part of the wireless mesh network; controlling, with the electronic processor, the software-defined radio to transmit an access request to one of the other radio nodes;and control, with the electronic processor, the software-defined radio to initiate the exchange of traffic data with one of the other radio nodes in response to receiving an access grant from one of the other radio nodes.

[0095] Example 17: The wireless communication procedure of Example 16, wherein controlling the software-defined radio to transmit the access request to one of the other radio nodes further includes determining an incoming dedicated control channel (DCCH) related to one of the other radio nodes from the first state information; and controlling the software-defined radio to transmit the access request to one of the other radio nodes on the incoming DCCH related to one of the other radio nodes from the first state information.

[0096] Example 18: The wireless communication procedure of Examples 16 or 17, further comprising the following steps: receiving a proposed TD_Map from one of the other radio nodes in response to the transmission of the access request; determining whether the proposed TD_Map is acceptable; in response to the determination that the proposed TD_Map is not acceptable, generating a second proposed TD_Map that is acceptable; and controlling the software-defined radio to transmit the second proposed TD_Map to one of the other radio nodes, wherein granting access is an acceptance of the second proposed TD_Map.

[0097] Example 19: The wireless communication procedure of Example 18, further comprising the following steps: determining an incoming dedicated control channel (DCCH) related to one of the other radio nodes from the first status information; controlling the software-defined radio to receive the proposed TD_Map on the incoming DCCH related to one of the other radio nodes; controlling the software-defined radio to transmit the second proposed TD_Map on the incoming DCCH related to one of the other radio nodes; and controlling the software-defined radio to receive the access grant on the incoming DCCH related to one of the other radio nodes.

[0098] Example 20: the wireless communication procedure of any of Examples 16 to 19, wherein the second status information includes connectivity matrices of the other radio nodes.

[0099] Example 21: the wireless communication procedure of any of Examples 16 to 20, wherein the second status information includes TD_Maps of the other radio nodes.

[0100] Example 22: the wireless communication procedure of any of Examples 16 to 21, wherein the second status information includes more usability faces of the other radio nodes.

[0101] Example 23: A non-transient, computer-readable medium comprising instructions that, when executed by a server, cause the server to perform a set of operations comprising: controlling a software-defined radio to transmit a pilot signal and first status information from at least one radio node of several radio nodes to other radio nodes of the several radio nodes that are part of a wireless mesh network; controlling the software-defined radio to gather pilot signals and second status information from other radio nodes of the several radio nodes that are part of the wireless mesh network; controlling the software-defined radio to transmit an access request to one of the other radio nodes;and control the software-defined radio to initiate a traffic data exchange with one of the other radio nodes in response to receiving an access grant from one of the other radio nodes.

[0102] This disclosure provides, among other things, systems, networks, wireless communication procedures, and non-transient computer-readable media with a CDMA-IA network operation concept and a media access control (MAC) layer. Several features and advantages of this disclosure are set forth in the following claims.

Claims

1. A wireless communication system comprising the following elements: Several radio nodes forming a wireless mesh network, in which pairs of the several radio nodes are configured to communicate with each other;At least one radio node of the multiple radio nodes includes a software-defined radio, a memory, and an electronic processor communicatively connected to the memory, and the electronic processor is configured to control the software-defined radio to transmit a pilot signal and first status information from at least one radio node to other radio nodes of the multiple radio nodes that are part of the wireless mesh network, control the software-defined radio to gather pilot signals and second status information from the other radio nodes that are part of the wireless mesh network, control the software-defined radio to transmit an access request to one of the other radio nodes, and control the software-defined radio to initiate traffic data exchange with one of the other radio nodes in response to receiving an access grant from one of the other radio nodes.

2. The wireless communication system of claim 1, wherein, in order to control the software-defined radio to transmit the access request to one of the other radio nodes, the electronic processor is further configured to determine a dedicated input control channel (DCCH) related to one of the other radio nodes of the first state information, and to control the software-defined radio to transmit the access request to one of the other radio nodes on the input DCCH related to one of the other radio nodes of the first state information.

3. The wireless communication system of claim 1, wherein the electronic processor is further configured to receive a proposed TD_Map from one of the other radio nodes in response to the transmission of the access request, determine whether the proposed TD_Map is acceptable, in response to the determination that the proposed TD_Map is not acceptable, generate a second proposed TD_Map that is acceptable, and control the software-defined radio to transmit the second proposed TD_Map to one of the other radio nodes, and wherein granting access is an acceptance of the second proposed TD_Map.

4. The wireless communication system of claim 3, wherein the electronic processor is further configured to determine a dedicated input control channel (DCCH) related to one of the other radio nodes from the first status information, control the software-defined radio to receive the proposed TD_Map on the input DCCH related to one of the other radio nodes, control the software-defined radio to transmit the second proposed TD_Map on the input DCCH related to one of the other radio nodes, and control the software-defined radio to receive the access grant on the input DCCH related to one of the other radio nodes.

5. The wireless communication system of claim 1, wherein the second status information includes connectivity arrays of the other radio nodes.

6. The wireless communication system of claim 1, wherein the second status information includes TDJMaps of the other radio nodes.

7. The wireless communication system of claim 1, wherein the second status information includes spectral usability masks of the other radio nodes.

8. The wireless communication system of claim 1, wherein the first status information includes a connectivity array of at least one radio node.

9. The wireless communication system of claim 1, wherein the first status information includes a TDJMap of at least one radio node.

10. The wireless communication system of claim 1, wherein the first status information includes a usability mask of at least one radio node.

11. The wireless communication system of claim 1, wherein the pairs of the various radio nodes are configured to communicate with each other and include the pairs of the various radio nodes that communicate indirectly with each other, using one or more additional radio nodes of the various radio nodes as repeaters, and wherein a repeater path is adaptively determined to maximize end-to-end network performance criteria, informed by a signal quality metric between the pairs of the various radio nodes.

12. A wireless communication network comprising the following elements: several radio nodes using time-division duplexing with a first period during which a first radio node transmits and a second radio node receives, and a second period during which the second radio node transmits and the first radio node receives, wherein a ratio between the first and second periods varies over time.

13. The wireless communication network of claim 12, wherein an adjustment of the ratio between the first and second period is made in response to traffic and interference conditions at the various radio nodes.

14. The wireless communication network of claim 12, wherein the various radio nodes include pairs of first and second radio nodes that communicate simultaneously with each other using the respective ratios of the respective first and second periods with more than one value.

15. The wireless communication network of claim 12, wherein the various radio nodes include first and second radio node pairs that communicate simultaneously with each other; each of these pairs uses a time-duplexing map that is optimized for each pair.

16. A wireless communication method comprising the following steps: controlling, with an electronic processor, a software-defined radio to transmit a pilot signal and first status information from at least one radio node of several radio nodes to other radio nodes of the several radio nodes that are part of a wireless mesh network; controlling, with the electronic processor, the software-defined radio to gather pilot signals and second status information from the other radio nodes of the several radio nodes that are part of the wireless mesh network; controlling, with the electronic processor, the software-defined radio to transmit an access request to one of the other radio nodes;and control, with the electronic processor, the software-defined radio to initiate the exchange of traffic data with one of the other radio nodes in response to receiving an access grant from one of the other radio nodes.

17. The wireless communication procedure 16, wherein the software-defined radio control to transmit the access request to one of the other radio nodes further includes the following steps: determining an incoming dedicated control channel (DCCH) related to one of the other radio nodes of the first state information; and controlling the software-defined radio to transmit the access request to one of the other radio nodes on the incoming DCCH related to one of the other radio nodes of the first state information.

18. The wireless communication procedure 16 comprising the following steps: receiving a proposed TD_Map from one of the other radio nodes in response to the transmission of the access request; determining whether the proposed TD_Map is acceptable; in response to the determination that the proposed TD_Map is not acceptable, generating a second proposed TD_Map that is acceptable; and controlling the software-defined radio to transmit the second proposed TD_Map to one of the other radio nodes; and wherein granting access is an acceptance of the second proposed TD_Map.

19. The wireless communication procedure 18 further comprises the following steps: determining an incoming dedicated control channel (DCCH) related to one of the other radio nodes from the first status information; controlling the software-defined radio to receive the proposed TD_Map on the incoming DCCH related to one of the other radio nodes; controlling the software-defined radio to transmit the second proposed TD_Map on the incoming DCCH related to one of the other radio nodes; and controlling the software-defined radio to receive the access grant on the incoming DCCH related to one of the other radio nodes.

20. The wireless communication procedure 16, wherein the second status information includes connectivity matrices of the other radio nodes.

21. The wireless communication procedure 16, wherein the second status information includes TD_Maps of the other radio nodes.

22. The wireless communication method of claim 16, wherein the second status information includes spectral usability masks of the other radio nodes.

23. A non-transient, computer-readable medium comprising instructions that, when executed by a server, cause the server to perform a set of operations comprising: controlling a software-defined radio to transmit a pilot signal and first status information from at least one radio node of several radio nodes to other radio nodes of the several radio nodes that are part of a wireless mesh network; controlling the software-defined radio to gather pilot signals and second status information from other radio nodes of the several radio nodes that are part of the wireless mesh network; controlling the software-defined radio to transmit an access request to one of the other radio nodes;and control the software-defined radio to initiate the exchange of 10 traffic data with one of the other radio nodes in response to receiving an access grant from one of the other radio nodes.;

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