SITIS Archives - Topic Details
Program:  SBIR
Topic Num:  N102-187 (Navy)
Title:  Spectrum Fragmentation of Networking Waveforms with Distributed Network Control
Research & Technical Areas:  Information Systems, Sensors

Acquisition Program:  JPEO JTRS ACAT I
 RESTRICTION ON PERFORMANCE BY FOREIGN NATIONALS: This topic is “ITAR Restricted”. The information and materials provided pursuant to or resulting from this topic are restricted under the International Traffic in Arms Regulations (ITAR), 22 CFR Parts 120-130, which control the export of defense-related material and services, including the export of sensitive technical data. Foreign nationals may perform work under an award resulting from this topic only if they hold the “Permanent Resident Card”, or are designated as “Protected Individuals” as defined by 8 U.S.C. 1324b(a)(3). If a proposal for this topic contains participation by a foreign national who is not in one of the above two categories, the proposal may be rejected.
  Objective:  Define candidate distributed algorithms and protocols for the physical, MAC and network layers in a mobile non-centralized network environment for fragmenting single-carrier modulation spectra into multiple non-contiguous mini-bands in response to regulations on bandwidth limits and spectrum unavailability as well as to local time-varying spectrum disturbances.
  Description:  Military Mobile Ad-hoc Networks (MANETs) such as Soldier radio Waveform (SRW), faced with the realities of decreasing electromagnetic spectrum availability both in the US and overseas, now need to address how to respond to and operate within these restrictions, as well as be able to adapt to locally encountered electromagnetic disturbances such as interference or multipath fading. To address the narrowing bandwidth challenge, MANETs have the option to reduce the data rate (or increase the modulation efficiency) to the point of satisfying new narrow bandwidth restrictions. Another solution would be to multiplex the modulation and break the spectrum into from 1 to N mini- bands each of which satisfies the BW limit and availability constraints, and whose aggregate throughput goes from 1/N to 1 of the single channel equivalent, depending on how many mini-bands were available. In wireless MANET networks when channel sensing technology becomes available, this capability will then need to be adaptive, so spectrum fragmentation will demand new protocols for distributing the channel and data rate allocation control among the network members. Commercial (centralized) wireless systems with base stations have a distinct advantage over decentralized control networks without infrastructure in adaptively controlling subscriber terminals. Moreover, IEEE continues to develop protocols addressing networks with less infra-structure and decentralized control such as in 802.16 (ref 1 & 2). However the problems of distributed network control for MANET networks continues to be an area that is not well known. Some prior solutions for decentralized control of GSM networks (ref 3) have been studied that may be useful in analyzing this problem with respect to the SRW. Because of the immediate pressing need for more spectrum flexibility to aid the spectrum authorization process, even a static solution without dynamic control will greatly increase the utility of SRW by making it possible to license in regions where it otherwise might be prohibited. Looking forward, spectrum sensing and dynamic spectrum access technologies are expected to be significant enablers of commercial and military wireless networks. The research requested here is intended to look at how spectrum fragmentation can be incorporated in the near term, and then to look at strategies that can solve electromagnetic problems, and how that strategy/algorithm can be shared and distributed in a non-centralized network. Some of the methods and protocols for this may be equally applicable to other MANETs such as WNW.

  PHASE I: 1) Establish a state of art baseline in spectrum fragmentation and adaptive net control technology, referring to the IEEE standards 802.16 (ref 1 and 2) standards as a minimum. 2) Synthesize candidate spectrum reshaping (fragmentation) approaches in response to bandwidth shaping commands to convert single modulated carriers with unimodal spectra into multiple non-contiguous unimodal mini-bands spread over a region of spectrum wider than the original carrier, where the sum of the mini-bandwidths do not exceed the original bandwidth. The solution should consist of cross-layer sub-band allocations, and channel multiplexing paradigms involving SIS, MAC, and Link layers. Assuming a MANET non-centralized network, for the identified approaches, synthesize allocation strategies when a pool of defined narrowband channels is made available (as opposed to being pre-assigned) requiring network wide control and information dissemination. 3) Using simulations provide performance data and discuss ease of implementation and compatibility with Mobile Ad-hoc Networking Waveforms and Software Defined radio architectures. Evaluate and rank the candidates in terms of performance benefit, ease of implementation and compatibility with MANETs.
  PHASE II: Develop, demonstrate and validate Phase I selected candidate algorithms and protocols. Generate a technology insertion plan for insertion into SRW. Build a test environment to demonstrate the recommended solutions including their network behavior for stressing environments appropriate to exercise the solutions. Update the net convergence and stability properties of the algorithms based on testing if necessary.

  PHASE III: Transition the implementation to the JTRS software environment, insert into SRW and perform development tests. Phase III will be Software Communication Architecture (SCA) compliant and also incorporate JTRS APIs as an application software package for JTRS sets. In addition, the software generated in this project is planned to be incorporated into the JTRS Enterprise Business Model, which allows JTRS vendors to utilize common software. PRIVATE SECTOR COMMERCIAL POTENTIAL/

  DUAL-USE APPLICATIONS: The techniques developed as part of this SBIR will greatly facilitate spectrum approvals of SRW with implications to WNW in the US and overseas in regards to wideband networking waveform licensing while the new protocols for distributed control developed here will also have applications to commercial wireless systems and extensions IEEE standards.

  References:   1. IEEE Standard 802.16d -2004 2. IEEE Standard 802.16e-2005 3. Implementation of a Low Cost Wireless Distributed Control System using GSM Network, Ganegedara, K.M.T.N, Jayalath, J.A. R.C., Kumara, K.M.K, Pandithage, D.N.U., Samaranayake, B.G.L.T., Ekanayake, E.M.N., Alahakoon, A.M.U.S.K., Industrial and Information Systems, 2008, ICIIS 2008, IEEE Region 10 and the Third International Conference on 8-10 Dec., 2008, pp 1-6.

Keywords:  wireless networks, distributed control, JTRS-SRW, spectrum fragmentation, adaptive, spectrum authorization

Questions and Answers:
Q: 1. Are you interested in PHY layer solutions as well as MAC layer solutions?
2. Would a response based primarily on novel but demonstrated spectral mapping be compliant?
3. Is privacy/encryption to be considered at this level, or are these concerns handled elsewhere?
A: 1. Yes.
2. Spectral mapping in both h/w and s/w is important, to include distributed decision-making.
3. Privacy / encryption is not the focus.
Q: Is there an Operating System requirement or preference for this project, or is it at the discretion of the tools used or at the developers option?
A: Updated 5/21/10: Developer's option, although Linux is preferred.
Q: 1. Are you looking for IEEE 802.16 family MAC layer, data link layer and physical layer protocal, something like how to divide (fragment) the super frame?
2. How long is the header, and what should be in header?
3. How long is the frame, and how many subframes?
4. How many bit for CRC code, subnet registration algorithm, sub channel allocation algorithm, member join subnet algorithm, and leave subnet algorithm?
5. Or just asking for how to fragment spectrum for spectrum and network management?
6. If it is the later one, will real time spectrum scanner be available?
7. Real time RF link Monitoring info available?
A: 1. Are you looking for IEEE 802.16 family MAC layer, data link layer and physical layer protocol, something like how to divide (fragment) the super frame?
Ans: Not necessarily. 802.16 may provide some useful ideas, but the MAC layer should be tailored to mobile ad hoc nets, peer to peer, coordination of fragmented spectra. It is not clear how much participation is required by a central net controller.

2. How long is the header, and what should be in header?
Ans: That is part of the design considerations and trades and is related to the method of spectrum fragmentation, It also relates to whether individual spectrum segments need to have independent channel estimators or whether they can be combined.

3. How long is the frame, and how many subframes?
Ans: No specific message structure needs to be assumed other than in the discussion of fragmented sync and equalization.

4. How many bit for CRC code, subnet registration algorithm, sub channel allocation algorithm, member join subnet algorithm and leave subnet algorithm?
Ans: Not defined. This detail is not necessary for answering topic 1 above. If it is needed in the MAC discussion, then make your own assumptions.

5. Or just asking for how to fragment spectrum for spectrum and network management?
Ans. Yes, see intro remarks above for topics 1 and 2.

6. If it is the latter one, will real time spectrum scanner be available?
Ans. If the need is dynamic and not static, then just assume that you are responding to some connected device with a spectrum scanner, but you do not need to worry about designing a specific dynamic spectrum control device.

7. Real time RF link Monitoring info available?
Ans. Links are always monitored to measure link thruput capacity in response to channel degradations.

Additional information from TPOC to clarify topic requirements:

The study has two sub-topics:
1) a trade study with simulation and analysis support into the most promising ways to fragment spectrum and then be able to reconstitute it, taking into account transmit distortion and channel multipath effects, considering such approaches as multicarrier modulation, OFDM, digital spectral decomposition and reassembly, etc. Also needs to address problems related to fragmented spectrum equalization and synchronization.
2) looking at possible MAC layer solutions. 802.16 or .22 are only mentioned to provide ideas, but generate a solution to address mobile ad-hoc peer-peer networks having some kind of low dynamic network controllers plus distributed network control by all nodes.

Fragmentation is done in response to any combination of the following: 1) static: contiguous bandwidth needed may not be available in different worldwide locations 2) dynamic: in response to some perceived interferer(s) or to avoid some specific user(s)) that may otherwise fall in-band.
3) Opportunistic cognitive radio controller utilizing unlicensed band white spaces.

Finally, the phase I should be able to provide enough guidance to select in a phase II a fragmentation approach and also a good start into the MAC distributed spectrum management control problem that would be engendered here.

Q: Does it include a peer to peer communication? Or, I can safely assume all user terminals communicate with a tower like cell phone?
A: The implicit basic networking paradigm for this Topic is peer-to-peer.

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