IL297176B2 - Wireless networks physical layer integrated access and fronthaul (iaf) - Google Patents

Description

Wireless Networks Physical Layer Integrated Access and Fronthaul (IAF) FIELD OF THE INVENTION [Para 1] This invention relates to Integrated Access and Fronthaul (IAF) engine and architecture for enhancing wireless Orthogonal Frequency-Division Multiplexing or multi carrier based and OFDM Access (OFDMA) networks (e.g., mobile, Wi-Fi) coverage, capacity, and localization. And more particularly the invention relates to a multiple access wireless cellular or/and Mesh network using Front-Haul (FH) split in the physical layer upgrading the efficiency, coverage, capacity, accurate localization, flexibility, and quality of service performance of radio access networks connecting a variety of wireless terminals.

BACKGROUND OF THE INVENTION AND PRIOR ART [Para 2] The IAF is a Wireless Node Repeater that can be installed on a pole, Light pole, Car or in a handheld unit or a Smart phone., The IAF receives signals from a Base Station (BS) or another IAF Node and after processing, transmits the related signals to the next IAF (Front-Haul) or to local End Users (Access). The IAF wirelessly multiplexes Access and Fronthaul data in Frequency, Time, Space and Code domains that handles the aggregated data using the same spectrum band for fronthaul and access and may have different carrier frequencies for transmit and receipt (FDD) or different time (TDM) or may have different or same OFDM Subcarriers, OFDM symbols, Beams, Code etc. or NOMA (Non-Orthogonal Multiple Access) OFDMA [Para 3] The IAF reuses and complements, the existing (e.g., 5G) wireless multiple access system components and interfaces. The IAF enables wireless connection with distributed remote radio-heads connecting wirelessly to the end user terminals.

[Para 4] The IAF splits/merges the high volume of traffic emerging/incoming a radio base-station to groups of related data. These groups are relayed to remote nodes where the group is restructured and either further relayed or wirelessly delivered to local end users.

[Para 5] The inter nodes relay and the end users' access are accomplished by using the same radio spectrum originally allocated for the end user's wireless access or on a separate frequency band.

[Para 6] In 5G several Radio Access Networks (RAN) split options were introduced, and two new splits were processed in the standardization committees: F1 at the 2nd layer of the 5G RAN protocol stack was processed in the Three Generation Partnership Project (3GPP) and 7.2x in the physical layer which was processed in Open RAN (O-RAN) Forum.

[Para 7] The transport of the data in these splits is done over fiber optics that require digging the ground and inserting cables for the required high data rate.

[Para 8] An effective replacement for such transport cables may be the use of a wireless backhaul/fronthaul. Such transport may be implemented out of the access radio bands or in band, sharing the access frequency bands. Such transport is a concept named Integrated Access and Backhaul (IAB).

[Para 9] State of the art wireless base stations tendency is using distributed units which connect with a Central Unit (CU).

[Para 10] The remote Radio Units (RU) are uncomplicated, slim radio elements which wirelessly connect locally distributed wireless End User (EU) terminals.

[Para 11] There are solutions where the RAN is split into a CU and a mid-unit - Distribution Unit (DU). The DU links the distributed RUs to the CU.

[Para 12] The network connecting the scattered RU’s can be accomplished by using fiber links (fiber optic (f/o) due to the high-rate throughput. Using such links complicates and increases the network infrastructure costs. This will be highly prominent at Millimeter-Waves (mmWave) bands where many miniature RUs shall be deployed at the service area.

[Para 13] For such cases an integrated wireless solution is greatly useful.

Current integration is accomplished at the higher layers of the RAN protocol stack.

[Para 14] An example for such integration is an IAB. Its basic concept is depicted in fig. 1, where the integration combines the wireless access along with the data backhauling over the same spectrum (generally allocated for access). See "Integrated Access and Backhaul in 5G mmWave Networks: Potentials and Challenges" by Michele Polese, Student Member, IEEE, Marco Giordani, Student Member, IEEE, Tommaso Zugno, Arnab Roy, Member, IEEE, Sanjay Goyal, Member, IEEE, Douglas Castor, Senior Member, IEEE, Michele Zorzi, Fellow, IEEE – June 2019).

[Para 15] IAB is a significant 3GPP Release 16 (Rel-16) feature in 5G New Radio (NR) standard that enables integrated deployments through self-backhauling using the access spectrum bands. IAB is implemented at the higher layers protocol stack split named F1 (between Packet Data Convergence Protocol (PDCP) and Radio Link Control (RLC)) layers, this IAB technique implies for each node including almost a full Base Station (BS) and a User Terminal.

[Para 16] IAF is a similar means, in the architecture sense, where the access and the X-hauling are accomplished in the physical layer using split 7.x which resides between the low physical and high physical layer. This architecture enables making the RAN DU a centralized small Edge Cloud connected to several, and more, RUs that carry out mainly the Multiple-Input and Multiple-Output (MIMO) weights precoding (optional), the Inverse Fast Fourier Transform (IFFT) and Digital to Analog conversion (D/A) connecting to the Radio Frequency (RF) transceivers.

[Para 17] In 7.2 split the transport connects high volume of coded and modulated data and controls linking the DU with the distributed RU’s. The large capacity prohibits wireless implementations.

[Para 18] State of the art wireless systems must handle a diversity of service profiles (enhanced Mobile BroadBand (eMBB) services, Ultra Reliable short latency services (URLLC) and Machine Type Communication (MTC) and Internet of Things (IoT) which induce various requirements and Key Performance Indicators (KPIs) to meet the users Quality of Service (QoS) and Quality of Experience (QoE) expectations at a wide range of deployment scenarios. Current solutions have difficulties in meeting concurrently such versatility. Novel solutions, as hereunder described, are required.

[Para 19] The invention introduces a method where the IAF processing is carried out in the physical layer of the wireless access network. All information bits are wirelessly transported over the fronthaul and the air-interface. Both, the wireless fronthaul and the access links, concurrently share the common air- interface spectrum.

[Para 20] The IAF spatially splits the high-volume data to several directions enabling spectrum reuse over several hops. Thus, a major improvement in wireless access systems is achieved, upgrading the coverage, capacity, flexibility, and quality of service of the access network connecting wireless terminals over the RAN.

[Para 21] The introduced system can work in low frequencies Non-Line-of-Sight (NLoS)/Line-of-Sight (LoS) and in mmWaves LoS and mix of F1 (sub 7.5 GHz) and mmWave bands (F2).

SUMMARY OF THE INVENTION [Para 22] A multiple access wireless cellular or/and Mesh system that uses Front-Haul (FH) split in the physical layer (for example between the FEC function and the FFT) where the edge radio unit called RU or RRH and the central unit connected through FO (Fiber Optic) cable called DU distributed unit. The DU distributed unit comprises a novel method to replace the wire by Wireless Fronthaul that transmits the FH signals over the air, instead of wireline, using wireless Integrated Access and Fronthaul (IAF) Units.

[Para 23] At least one IAF unit, that relays/routes the signal Front-Haul to various directions on the path from the source to the destination, wherein the system is configured to including (one or more) IAFs relay/router units for improving the coverage and/or range and/or capacity of the cellular/Mesh system topology thus avoiding radio frequency signal obstruction.

[Para 24] The system supports a wide access cell-free wireless concept where a user may be connected through several IAF units at the same time or switch between them on the fly. In the system coverage area, there is no need for hand- off process to handle a moving user terminal.

BRIEF DESCRIPTION OF THE FIGURES [Para 25] Fig.1 – is a block diagram of IAB Basic Architecture and Related Protocol Stack – prior art. 20 [Para 26] Fig.2 – is a typical wireless access network architecture implementing distributed access via IAF elements.

[Para 27] Fig. 3 - is a block diagram of IAF transport and access chain.

[Para 28] Fig. 4 –is a block diagram of the IAF Engine Mechanism.

[Para 29] Fig. 5 - is a block diagram of an access network including 2 IAF consecutive hops layout.

Detailed Description of The Figures [Para 30] The present invention relates to the field of an integrated wireless solution accomplished at the lower layer of the RAN protocol stack.

[Para 31] The present invention discloses novel IAF routes information from/to several sources, comprising:  The Distribution Unit (DU) 110.

 The wireless end terminals (e.g., User Equipment (UE)’s, IoT terminals 103).

 Distributed IAF units 200.

[Para 32] The traffic (user data, control, synchronization, and management) is routed over the links connecting DU 110, IAF units 200 and end terminals103, as presented in fig.2, being a typical wireless access network architecture implementation.

[Para 33] In fig.2, DU 110 connects the distributed IAF units 200 via an IAF Rooting unit 201. Unit 201splits the incoming high rate from DU 110 into several transport beams 202 linking with distributed IAF units 200. The Rooting unit 20 201interface with DU 110 may be implemented by using 5G split 7.X 206 (e.g., 7.1 or 7.2) options, as defined by O-RAN forum (fig. 3).

[Para 34] Splits 7.X are placed in the physical layer between the slot Resource Elements (RE) mapping 204 and the Digital Beamforming (BF) processing 202.

[Para 35] At the Down link (DL) an allocations map of OFDMA (I, Q) Resource Elements which are routed to a common (or few) antennae port/s may be either relayed or handed for local access. If relayed, these map/s will be linked by an allocated transport beam/s connecting the origin with the next IAF units202. [Para 36] Rooting unit 201 comprises many transport beams 202 directed to the distributed IAF units 200. These beams 202 are directional and may run in parallel. The massive traffic is processed at Rooting unit 201.

[Para 37] Each beam 202 may handle at least two allocation maps using the cross-polarized antennae 100.

[Para 38] The IAF (200) unit's engine will split the incoming RE maps as assigned by the central Media Access Control (MAC) layer (being part of DU 110), either to a transport beam 202 or a local access beam 203.

[Para 39] When necessary, more than two transport beams 202 may be assigned at an IAF (carrier aggregation) 200.

[Para 40] The above architecture accomplishes the transport part by routing the user’s digital modulated data over few hops and up to the closest IAF next to end user's terminal 103 as set and supervised by MAC Layer 302. The IAF units 200 carries out the transmission at the allocated time, frequency and antennae port as set by the central MAC scheduler 303 (fig. 4).

[Para 41] MAC 302 algorithms are designed to optimize the routing (minimize the hops count from rooting unit 201 to access beam 202) and enhance the reliability and throughput and QoS. MAC 302 uses channel indications and measurements provided by IAF units 200 and UEs 103 to carry out this task.

[Para 42] The IAF engine is rooted in the space directivity, polarization, frequency, code and time domains processed at the low physical layer of the wireless network protocol stack (see fig. 1).

[Para 43] The engine processes resource elements (RE) maps directing RE's to its destination which can be local access or at neighboring IAF units using transport beams 202.

[Para 44] Processing is based on incoming RF signals zero RF conversion, FFT 301 and baseband OFDMA sub-carrier groups as detailed below 304 is remapping the digitized signals in the frequency and time domains (Regeneration).

[Para 45] A Section is a group of allocated resource blocks in frequency extending over few OFDMA symbols time. Sub-Section is part of the section related to one symbol time. Incoming maps Sub-Sections are reallocated and mapped according to outgoing beams for transport or allocated for local access, as controlled by central MAC 302. Using baseband 304 groups regeneration streamlines and shortens the IAF processing.

[Para 46] Fig. 4 presents the IAF core block diagram. In green are the transport parts 300 & 301 while in gray are the access parts 305.

[Para 47] To enhance the access network performance remodulation may be included, such as: For higher Signal-to-noise ratio (SNR) in the next hop receiver, transport beams 202 for the next beam may use higher modulation schemes (enhance capacity).

This will, on one hand increase transport links capacity and performance but on the other hand it increases complexity and needs more control information bits.

[Para 48] Sections which are directed to local users are processed for local access at the IAF. These sections shall be beamed to the direction where the users are placed using the system common (e.g., 5G) air-interface.

[Para 49] This process includes pre-coding, beamforming, IFFT plus Cyclic Prefix (CP) addition, digital to analog conversion and RF 301. These processes are accomplished by using the Control Plane, (detailed below), information preceding the User Plane data.

[Para 50] Beams directed to neighboring IAF units will be formed for transporting to the designated IAF direction. The beam forming process shall use preset weighting parameters (the DU, RU and IAF units are static thus directions may be pre-calculated and preset digital weights may be set at the initialization process). Transport direction selection are controlled by the upper layers of the protocol stack (e.g., MAC layer 302). The selected direction is signaled by related control data using Control Plane RE groups located at a preconfigured locations at the RE map or at section's header fields. The above concept is depicted in fig.3.

[Para 51] To deliver complementary control, timing and synchronization, power level, antenna elements weights and management flows information directed to the IAF, includes pre-allocated, reserved per IAF, resource elements (e.g., preset part of the RE map 3rd symbol) groups which include structured control data.

[Para 52] Each IAF will have a pre-allocated range where its related control timing and synchronization information shall reside.

[Para 53] Following detection of these bits, the IAF shall acquire the relevant information for synchronization and incoming sections maps routing (map may be destined for local UEs or for neighboring IAF units).

[Para 54] For local UEs 103, RE map is processed the same as for regular standard RU. For neighboring IAF, destined maps are linked using a preset directed beam 202, formed to link with designated IAF units 200.

[Para 55] If required, one or more hops may be accomplished. To keep the delay low, mini slots (202) may be used, and/or by using higher sub-carrier spacing, to shorten the slot duration (see fig. 5).

[Para 56] For low latency service sections, IAF chain bypass may be accomplished using adaptive power control to extend the range and minimize the hop count.

[Para 57] The Up Link (UL) shall be controlled by the central MAC 302 using the same mechanism.

[Para 58] The routing of RE maps is set by the central MAC (302) layer. To guide the physical layer units how to handle each incoming map, related control information is delivered to the IAF unit indicating whether it is for local access or as neighbors RF link and to which antenna port (in case of multi-beam).

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [Para 59] Although embodiments of the invention are not limited in this regard, discussions utilizing terms such as, for example, "controlling" "processing," "computing," "calculating," "determining," "establishing", "analyzing", "checking", "setting", "receiving", "Base Station", "Nodes", "RRH", "RU", "Radio Heads" or the like, may refer to operation(s) and/or process(es) of a controller, a computer, a computing platform, a computing system, a cloud computing system or other electronic computing device, that manipulates and/or transforms data represented as physical (e.g., electronic) quantities within the computer's registers and/or memories into other data similarly represented as physical quantities within the computer's registers and/or memories or other information non-transitory storage medium that may store instructions to perform operations and/or processes.

[Para 60] Unless explicitly stated, the method embodiments described herein are not constrained to a particular order or sequence. Additionally, some of the described method embodiments or elements thereof can occur or be performed simultaneously or concurrently. 20 [Para 61] A multiple access wireless cellular or/and Mesh system that uses Front-Haul (FH) split in the physical layer (for example between the FEC function and the FFT) where the edge radio unit called RU or RRH and the centralized unit which is connected through FO (Fiber Optic) cable called DU distributed unit.

[Para 62] A novel system to replace the wire by wireless fronthaul that transmits the FH signals over the air, instead of wireline, using wireless Integrated Access and Fronthaul (IAF) Units. The IAF unit, relays/routes the signal Front- Haul to various directions on the path from the source to the destination.

[Para 63] The system is configured to include (one or more) IAFs relay/router units for improving the coverage and/or range and/or capacity of the cellular/Mesh system topology thus avoiding radio frequency signal obstruction.

[Para 64] The DU, distributed unit, multiplexes access and fronthaul data in frequency, (for example: in subcarriers resolution in case of OFDMA), time and space domains, and handles the aggregated data using the same spectrum band.

[Para 65] IAF units reuse and complement existing wireless access (e.g., 5G) components and interfaces and enable concurrently the IAF units to connect wirelessly with local users' terminal and transport user and control planes information signals to distributed remote radio-heads, connecting remote fielded end user terminals.

[Para 66] The IAF operates in sub-7.5GHz frequencies (F1), or in mmWaves, or in a mix of F1 and F2 including initial access and broadcast channel.

[Para 67] The IAF splits/merges and routes the high volume of traffic emerging/incoming a radio base-station to groups of related data. The group members are related by the wireless connection propagation, channel quality attributes (e.g., propagation, location, delay, interference) of end users near or far Line of Sight (LOS) or no LOS (NLOS) and/or number of IAF hops.

[Para 68] The related data groups are relayed/routed to remote nodes where the groups are restructured and wirelessly delivered to the local members end users or further transported to other nodes.

[Para 69] The IAF splits the physical layer by using Split physical leaving the FEC function in the network part and the OFDM Modulator/Demodulator and RF in the edge part, using, for example, O-RAN split 7.2. The split interface is used as the anchor point for routing the outgoing/incoming data signals to the deployed IAF units.

[Para 70] The inter nodes relay and the end users' access is accomplished by using the same radio spectrum, originally allocated for the end user's wireless access, and the radio spectrum allocated for end user's equipment access is reused also for transport of the end user's data, control and synchronizing information over the IAF network infrastructure.

[Para 71] The IAF mechanism processes regenerated maps of OFDMA Resource Elements (RE). The IAF engine restructures the incoming RE maps and redirects RE blocks, as controlled by the central MAC, either to local access (for example: terminal, phone) or to a neighboring IAF unit using transport beams directing the signal to its next hop.

[Para 72] The processing is based on incoming RF signals converted to digital Intermediate Frequency (IF) (can be Zero IF) conversion and digital FFT to frequency domain and baseband OFDMA sub-carriers, remapping in the frequency and time domains using same or different OFDM symbols at the resource elements map.

[Para 73] The remodulation is included as part of the regeneration process to enhance the network performance throughputs, delay etc. for higher Signal to Noise Ratio (SNR) in the next hop.

[Para 74] The transported data may use higher or lower modulation schemes adapted to the expected channel conditions that increase transport links capacity, enhancing performance but increasing complexity and require more signal processing and control information bits.

[Para 75] The remote IAF units, (remote from rooting unit), due to its expected diluted Resource Element (RE) maps, the modulation scheme may be decreased to cope with degraded access channels or for decreasing transport link RF power to minimize interference.

[Para 76] For enhancing end to end performance, signals are transported in parallel at various directions to boost its resilience, whereas for static infrastructure deployment the antennae beam-forming process uses preset beamforming weighting parameters.

[Para 77] For mobile IAF units, beams weights parameters are dynamically calculated using units' updated location.

[Para 78] The transport direction selection (next hop) is controlled by the upper layers of the network protocol stack (e.g., MAC layer), and the selected direction is signaled by related control data using control RBs (Resource Blocks) nested at a preset location in the RE map or at related data frames header fields.

[Para 79] In order to keep the end-to-end delay low, mini slots may be used and/or higher frequencies of sub-carrier spacing to shorten the slot duration.

[Para 80] Shortening the delay of an urgent session, may be achieved by chain bypassing accomplished by using adaptive RF power control to extend the urgent session (Physical Data Unit) PDU's range and minimize the hops count for critical use cases.

[Para 81] Managing the Broadcast Channel (BCH) proper frame numbering may be performed by pre-recorded BCH slots stored at the IAF unit's memory, these BCH slots are transmitted at the right timing and coordination with the slots frame numbering.

[Para 82] Managing the Broadcast Channel (BCH) sub-frame proper numbering may also be carried out by using a fast delivery (w/o processing at the IAF units) of the BCH symbols.

[Para 83] To avoid BCH blocks wrong detection, an additional scrambling may be used to avoid detection at intermediate nodes and user terminals, and this extra scrambling is removed at the last node linking the destination end user terminals.

[Para 84] The routing and control of the OFDMA Front-Haul signals is accomplished by using centralized or distributed control, or by mixed using, for example, distributed (ML) Machine Learning, (AI )Artificial Intelligence ML/AI or other methods.

[Para 85] In the multi hop OFDMA signal the data sub-carriers along with the training pilots are running together through the same IAFs channel links to enable the carrying out proper data detection at the end (for example, at the user terminal) and the FEC decoder is running together only in the last hop.

[Para 86] The signals routing and the Tx Power set at each IAF node of the OFDMA Front-Haul is accomplished by a centralized or distributed control, or by mixed method using, for example, distributed ML/AI.

[Para 87] The creating of a virtual beam forming massive MIMO and several parallel data streams is performed by sending the different streams over different directions receiving them in the directed IAF units, which redirects them to the multi beam receiver in the IAF or to an end terminal which supports MIMO reception or any multi beam receiver.

[Para 88] Using the IAF topology to support Multi Beams and optimize the direction and redirection is performed by controlling the transmitting and the receiving beams direction and/or power and/or time alignment of the wireless IAF signals.

[Para 89] The IAF duplex is using FDD (Frequency Division Duplex) or TDD (Time Division Duplex) or Full Duplex.

[Para 90] FDD- is where the reception is at one frequency and the transmission is at a different frequency at the same time, applicable for achieving very low latency and network.

[Para 91] TDD – is where the reception and the Transmission are at different slot time, while in the disclosed invention, this time interval is very low.

[Para 92] Full Duplex - is where there is one allocated frequency band, and the transmission and reception are at the same time and in the same frequency. The transmitted signal is dynamically subtracted isolating the Tx antenna from the Rx antenna by splitting the resources in allocated subcarriers for Tx and Rx subcarriers and allowing the signals from other IAF units or user terminals to go through with good SNR.

[Para 93] For time alignment- in multi hop configuration several delays may aggregate to a long interval if an additional delay of the processing in the IAF is included. A method of time interval offset in the length of the aggregated OFDM symbols time is included. That is accomplished due to the pre-known location of the IAF network units, so that only the delay of the air access part will influence the range alignment carried out by the system control.

[Para 94] A special positioning signal for each IAF unit is scrambled with the IAF ID and distributed. This signal is transmitted every few time intervals in a frame, slot, OFDMA symbol and pre-defined allocated RBs as configured in advance or periodically by the network. Each user has prior information on several transmitter's location and can use it for localization and mapping calibration. Each IAF will try to decode and estimate the time of arrival relative to its internal timing clocks or measure differential time of arrival between different IAF or UE's received signal and measure the SNR, the IAF ID, direction and the RSSI. All these localization measurements are transferred to a central unit (e.g., a server) having prior information on location of several of the transmitters or, in case of a distributed approach, the server has prior information on the location from where each IAF receives the transmitted localization messages and calculates internally elements' new positions. The pre-known information is used to train and calibrate the network and enable calculating the unknown location of user's terminals.

[Para 95] The information of users' location is broadcasted (may be pre- encrypted) to all or part of the users (e.g., terminals at proximity with distributed source location) and the users may use that information to calculate online their location internally or by fast corrections on its received location. After receiving several IAF transmission updates and calculating its position by using methods of differential time of arrival or other methods which may include AI.

[Para 96] In OFDMA it is required in the uplink that the signals multi-path components which are related to the same symbol will arrive within the symbol CP (Cyclic Prefix). In order to do that a (Time Alignment) TA procedure may be used. In the current disclosure, a user terminal needs to switch the transmit routing on the fly and accordingly needs to shift the transmit time according to the updated propagation and the RF process delay over each hope.

[Para 97] The above procedure enables the end terminals to enhance and expedite its ranging process calculating its time alignment advance from its related IAF unit and broadcasted information. This wide alignment process improves its signal detection by the IAF unit. The information of the TAs is distributed to other terminals and IAF units and is further processed when required.

[Para 98] The routing algorithm is a novel scheduling and routing algorithm learning the effect of each transmitted signal over its neighbors using the localization data and accordingly allocating the transmitted signals at each time interval to efficiently reuse the radio resources and maintain spectrum sharing meeting effective for the required QoS performance, (the method referred to as "Forward Scheduler").

Claims (26)

Claims

1. A multiple access wireless cellular and Mesh system using Front- Haul (FH) split in the physical layer wherein the edge radio unit (RU or RRH) and the centralized unit are connected through Fiber Optic cable (DU distributed unit) comprising at least one Integrated Access and Fronthaul (IAF) unit, relaying or routing the signal Front-Haul to various directions on the path from the source to the destination, wherein the system is configured to: including (one or more) IAFs relay or router units for improving the coverage, range and capacity of the system topology thus avoiding radio frequency signal obstruction; multiplexing access and fronthaul data in frequency, time and space domains; and handling the aggregated data using the same spectrum band; reusing and complementing existing wireless access (such as 5G) components and interfaces by IAF units; and enabling concurrently the IAF units to connect wirelessly with local users' terminal and transport user and control planes information signals to distributed remote radio-heads connecting remote fielded end user terminals; Wherein the IAF operates in sub-7.5GHz frequencies (F1), or in mmWaves (F2), or a mix of F1 and F2; including initial access and broadcast channel.

2. The system of claim 1 wherein the IAF splits or merges and routes the high volume of traffic emerging and incoming a radio base-station to groups of related data, whereas the group members are related by wireless connection propagation, channel quality attributes (such as propagation, location, Delay interference) of end users near or far Line of Sight (LOS) or no LOS (NLOS) or number of IAF hops.

3. The system of claim 1 and 2 wherein the groups are relayed or routed to remote nodes where the groups are restructured and wirelessly delivered to the local members end users or further transported to other nodes.

4. The system of any one of claims 1-3 wherein the inter nodes relay and end users' access is accomplished by using the same radio spectrum, originally allocated for the end user's wireless access, and the radio spectrum allocated for end user's equipment access is reused also for transport of end user's data, control and synchronizing information over the IAF network infrastructure.

5. The system of any one of claims 145 wherein the IAF mechanism processes regenerated maps of OFDMA Resource Elements (RE), the IAF engine restructures the incoming RE maps and redirects RE blocks, as controlled by the central MAC, either to local access (like: terminal, phone) or to a neighboring IAF unit using transport beams directing the signal to its next hop.

6. The system of claim 5 wherein the processing is based on incoming RF signals converted to digital Intermediate Frequency, (IF) (may be Zero IF), and digital FFT to frequency domain and baseband OFDMA sub-carriers remapping in the frequency and time domains using same or different OFDM symbols at the resource elements map.

7. The system of any one of claims 5-6 wherein remodulation is included as part of the regeneration process to enhance the network performance for higher Signal to Noise Ratio (SNR) in the next hop.

8. The system of claim 7 wherein the transported data may use higher or lower modulation schemes adapted to the expected channel conditions that increase transport links capacity, enhancing performance but increasing complexity and requiring more signal processing and control information bits.

9. The system of claim 7 wherein for remote IAF units (remote from rooting unit) due to its expected diluted Resource Element (RE) maps, the modulation scheme may be decreased to cope with degraded access channels or for decreasing transport link RF power to minimize interference.

10. The system of claim 9 wherein for enhancing end to end performance, signals are transported when bandwidth is available at adequate transport links, in parallel via various directions to boost the transport resilience, whereas for static IAF infrastructure deployment, the antennae beam-forming process uses pre-set beamforming weighting parameters and for mobile IAF infrastructure, beams weights parameters are dynamically calculated using IAF units' updated location. .

11. The system of any one of claims 1-9 wherein the transport direction selection (next hop) is controlled by the upper layers of the network protocol stack (e.g., MAC layer), and the selected direction is signaled by related control data using control RBs (Resource Blocks) nested at a preset location in the RE map or at related data frames header fields.

12. The system of any one of claims 1-11 wherein keeping the end- to-end delay low, mini slots may be used or higher frequencies of sub-carrier spacing to shorten the slot duration.

13. The system of any one of claims 1-12 wherein for shortening the delay of an urgent session, end-to-end low delay may be achieved by chain bypassing and using adaptive RF power control to extend the urgent session (Physical Data Unit) PDU's range and minimize the hops count for critical use cases.

14. The system of any one of claims 1-13 wherein the managing of the Broadcast Channel (BCH) proper frame numbering, may be performed by pre-recorded BCH slots stored at the IAF unit's memory, these BCH slots are transmitted at the right timing and coordination with the slots frame numbering.

15. The system of any one of claims 1-14 wherein the managing of Broadcast Channel (BCH) sub-frame proper numbering may be performed by using a fast delivery (w/o processing at the IAF units) of the BCH symbols.

16. The system of any one of claims 1-15 wherein avoiding BCH blocks wrong detection, an additional scrambling may be used to avoid detection at intermediate nodes and user terminals, and this extra scrambling is removed at the last node linking the destination end user terminals.

17. The system of any one of claims 1-16, wherein in the multi hop OFDMA signal, the data component carriers with the training pilots are running together through the same IAFs channel links to enable the carrying out of data detection at the user terminal), and the FEC decoder is running together only in the last hop.

18. . The system of any one of claims 1-17 wherein the signals routing and the Tx Power set at each IAF node of the OFDMA Front-Haul is accomplished by a centralized or distributed control, or a mixed using, and may be using distributed ML/AI or any other distribution method.

19. The system of any one of claims 1-18 wherein the creating of a virtual beam forming massive MIMO and several parallel data streams is by sending the different streams over different directions receiving them in the directed IAF units which redirects them to the multi beam receiver in the IAF or to an end terminal supporting MIMO reception or any other multi beam receiver.

20. The system of any one of claims 1-19 wherein controlling the transmitting and the receiving beams direction and optimizing the direction and redirection or power or time alignment of the wireless IAF signals, by using the IAF topology to support multi beams.

21. The system of any one of claims 1-20 wherein the IAF is used as FDD (Frequency Division Duplex), or TDD (Time Division Duplex), or Full Duplex.

22. The system of any one of claims 1-21, wherein a method of time interval offset in the length of OFDM symbols time integer multiple is included and accomplished by pre-knowing the location of the IAF network units, so that only the over delay of over the air access influence the range alignment carried out by the system control.

23. The system of claim 22 wherein a special positioning signal per each IAF unit is scrambled and distributed with the IAF ID, . transmitting by the network either periodically or every few time intervals in a Frame, Slot, OFDMA symbol and pre-defined allocated RBs as pre-configured.

24. The system of claim 23 wherein each IAF tries to decode and estimate the time of arrival relative to its internal timing clocks (e.g., the SNR the IMF ID, and the RSSI) transferring all these measurements to a centralized unit (e.g., the server) having prior information on location of several of the transmitters.

25. The system of claim 24 wherein the information of users' location, that may be pre-encrypted, is broadcasted to all or part of the users being at user's terminal proximity. The system of claim 26 wherein a Time Alignment (TA) procedure may be used, where a user terminal needs to switch its transmit routing on the fly and accordingly needs to shift its transmit time according to the updated propagation and the RF process delay over each hope.

26. The system of claim 25 wherein the information of the TAs is distributed to other terminals and IAF units and is compensated when required.