DARPA-BAA-15-24_Q_and_As_04.13.15.docx

DARPA BAA-15-24

Shared Spectrum Access for Radar and Communications (SSPARC) Coexistence Phase 2 Questions &Answers

ACRONYMS / DEFINITIONS FOR THIS DOCUMENT

Question 1: Given metrics that evaluate military MANET nodes in pairs, how does DARPA anticipate evaluating the 3 node experiments?

All node pairs transfer data continuously. All pairwise data connections must maintain acceptable performance.

Question 2: What is the expectation regarding the number of lab and demonstration setups required under the program? For example, will there be more than one demonstration platform for measurement and VIP demos?

It is up to the proposer.

Question 3: Is it permissible to conduct a field experiment in the base effort?

The BAA specifies only the minimum requirements for the research sought.

Question 4: Please confirm the number of separation techniques and devices required for simulation, lab tests, and field demonstration.

See table below.

Minimum number of separation techniques

Minimum number of communications devices (MANET type, LTE type, WiFi type)

Question 5: Section 1.3 states "DARPA does not anticipate providing any equipment as GFE for Phase 2." What about a request for DARPA to provide access to a test range where there is a radar, and provide test time, so the performer can evaluate their solution operating in conjunction with that radar (which is unmodified).

The proposer may make such a request in their proposal.

Question 6: Bob Schneider's presentation at the Industry Day referred to a recent NTIA proposal for radar/communication spectrum sharing, filed in FCC 3.5 GHz proceeding. Where can this proposal be found?

The NTIA letter (FCC docket 12-354, filing submitted 3/24/2015, attorney Stacy M. Cheney) may be found at http://apps.fcc.gov/ecfs/comment/view?id=60001027385. There are 3 parts all linked from that page.

Question 7: What is the influence of the expected FCC 3.5 GHz order on the SSPARC program.

It is anticipated that the FCC approach will set the baseline standoff distance against which SSPARC should show improvement in Phase 3 when applied to the same radar and communications systems.

Question 8: The BAA discusses solution comparison based on comms throughput. How will models/scenarios be compared for apples-to-apples evaluations? Are there other dimensions of evaluation? Cost, complexity, OPSEC?

The BAA defines the metrics that will be used to assess proposed systems.

Question 9: In the handover field trials, how many mobile devices should we assume are in the small cells. (Context: Handover in heavily-loaded, interfered cells is much more challenging than if there is only a single mobile device.)

Lightly loaded small cells are acceptable for the phase 2 demonstration. The technology approach should be capable of handling heavily loaded cells.

Question 10: In a commercial communications system, individual device throughput is also important. Besides the total throughput from an eNodeB, should individual device throughput be evaluated too? Especially devices at cell edge. Other parameters for commercial users could include handover related and outage rates for specific applications. Will the results be considered & evaluated if we provide them?

BAA section 1.2 states "Proposers are encouraged to provide additional parameters to measure during Phase 2 that effectively characterize the spectrum access benefits of their technologies or system solutions in comparison to the existing state of the art."

Question 11: Will DARPA attempt to compare performance between different military MANETs.

No.

Question 12: Is exploitation of propagation shadows considered a third separation technique?

BAA Section 1.1.1 lists candidate separation mechanisms.

Question 13: Re the proposer's day briefing, should "distance D" be "distance S" on slide 57, last bullet?

Yes.

Question 14: Please tell me how this program differs from other DOD, first responder, and DARPA programs. Bob Schneider's Industry Day presentation mentioned Commercial dynamic allocation initiatives. In regard to spectrum management & awareness (i.e. AFCSS (automatic fixed channel sensing and selection), self organizing networks (SON), neXt Generation communications (XG), Naval Research Laboratory Joint Counter Improvised Explosive Device Electronic Warfare (NRL JCREW), and Army announcements etc.)? Do these other programs have a radar component? Are there similar general principles?

BAA section 1.1.1 states, "SSPARC treats spectrum sharing as a cooperative problem."

Question 15: Please describe the coordination, both current and planned, with the National Spectrum Consortium.

No coordination with the national spectrum consortium is planned for this program.

Question 16: Would the government extend the proposed deadline by 1 month to enable contractors to study and research the phase 1 final reports?

No.

Question 17: If a subcontractor partners on multiple proposals, and more than one is selected for award, may the subcontractor perform on multiple Phase 2 teams?

Yes.

Question 18: May a proposed solution incorporate hardware modifications or upgrades to communications devices?

Yes.

Question 19: May a proposed solution incorporate standalone RF sensing devices that would be deployed in addition to the radar and communications equipment.

Yes.

Question 20: Are there specific cellular LTE modes that are requirements? Modes might be Frequency Division Duplex (FDD), Time Division Duplex (TDD), carrier aggregation, with and without Multi Input Multi Output (MIMO), LTE advanced? Which release dates (standards versions) are required?

The system designed in Phase 2 should address the problems that will arise in real-world spectrum sharing situations. Standard versions are up to the proposer (see BAA section 1.1.8).

Question 21: Is SSPARC phase 2 considering decentralized (distributed) information sharing to better support events such as MANET subnet convergence and multiple radar systems? The overview of Phase 1 efforts appeared to indicate a single, centralized control system and a single radar being deconflicted with communications.

The system designed in Phase 2 should address the problems that will arise in real-world spectrum sharing situations.

Question 22: Can we assume that our phase 2 system solution is applied research? What would cause it to be classified otherwise?

See BAA section 2.1.

Question 23: OPSEC was stressed as an important aspect of system design. However, it does not appear in the evaluation criteria. Is the expectation that the security mechanism be mature technology, or will emerging security technology be entertained?

Within the context of a proposal that covers all 8 work topics of the BAA, research on any technology that is a critical enabler for achieving program goals may be proposed.

Question 24: May a proposer submit a classified appendix? Does it count against the page limit?

A proposer may submit a classified appendix; see BAA section 4.2.1. Content pages in a classified appendix count against the page limit, but header pages, Table of Contents, etc. do not.

Question 25: Is it permissible to offer an option to perform work on Electronic Protection benefits to the radar using the comms network as a distributed Electronic Support Measures (ESM) receiver.

Yes.

Question 26: Are the two 9 month work periods consecutive or concurrent.

Consecutive.

Question 27: How much of the work to develop commercial implementations of the SSPARC technology is within scope of the DARPA funded program?

DARPA seeks to fund the minimal amount of work on the commercial side required to stimulate commercial industry to adopt the technology and bring solutions employing it to market.

Question 28: The BAA cites "high fidelity" simulations to be used to integrate and test the susceptibility of the system to the red-team jammer. Do you intend to implement the red-team jammer into an end-to-end (discrete event) simulation or a "high fidelity" radar only simulation (e.g. a waveform-level simulation).

Both end-to-end and waveform-level simulation are required, but they may be separate.

Question 29: Please clarify the requirement regarding the reference code for a jamming attack that should be delivered in the base effort. (1) Is the performer required to design an attack? (2) If so, what kind of jamming is required in the reference attack (noise jamming; false target generation; etc.)

The reference code should show the red team how to carry out an attack of the following form. From multiple collaborating specified locations in the area of operations, carry out the following sequence of steps. (a) Observe radar behavior and information sharing subsystem traffic over a long period of time (minutes). (b) Carry out noise jamming, replay attacks, or new data injection attacks on the information sharing subsystem wireless links. (c) Carry out radar jamming involving noise, arbitrary waveform generation, or transmitting copies of monitored signals. Step (c) must be supported by a waveform level (I/Q data) simulation. Steps (a) and (b) may be simulated at packet or pulse level to reduce simulation time, as long as the simulated state can be transferred into the waveform level simulation when the attack code decides to initiate step (c). Monitoring of or transmitting into information sharing subsystem wireless links must be supported at packet level even in the waveform level simulation, so the red team does not have to build receive or transmit signal processing chains for those links. Both packet/pulse level simulation mode (if present) and waveform level simulation mode should enable the attack code to precisely control the timing of transmissions.

Question 30: Will the red team attack strategy be shared with the performer in advance of the assessment?

No.

Question 31: What layers/system components will the red team attack?

The attacks will be against perceived vulnerabilities introduced by the sharing mechanism. Any attack surface meeting that criteria, on any system component, is within scope. However, cyber attacks are not in scope in this phase. (For definition of "cyber attack", see next question).

Question 32: If upper layers such as MAC are attacked, that appears to be like a cyber attack. What is the definition of a cyber attack that has been ruled out?

The only form of attack that has been ruled out is code modification.

Question 33: Are jamming attacks against the data link between the radar and communications system within the threat model that the SSPARC design should defend against.

Yes, as per BAA Section 1.1.4 statement that one important issue for research is "graceful performance degradation in situations where the data link is intermittent or unavailable." However, research on making a communications link anti-jam is not within scope of this BAA. Approaches that employ existing anti-jam solutions are preferred.

Question 34: Slide #42 re: "DARPA may specify tests that require simulation of common radar and communication systems." What level simulation of common radars are required? Will any GFI be provided regarding these radars? When will scenario details and interface formats be provided (e.g. months after contract award) to the teams?

The simulation level should permit assessment of applicable BAA metrics. The government will provide specifications of the common systems and scenarios no later than 1 month after contract award.

Question 35: Sec 1.1.4 p. 11 of the BAA describes the S-band radars that are to be considered. Among these is the SPN-43 type. We understand that a SPN-50 radar is being considered as a replacement. Will we need to consider the SPN-50 radar in this phase of SSPARC.

The BAA specifies only the minimum requirements for the research sought. The proposer may study additional radars.

Question 36: How will the propagation environment/scenario be defined. Is the shadowing in the scenarios to be defined by the government or by the proposer/contractor?

For simulations intended to support comparison across performers, the government will specify the propagation environment and scenario. For other simulations, it is up to the proposer, subject to review and approval by DARPA.

Question 37: Shadowing and propagation exploits are mentioned as key sharing techniques, but the metrics and experiments appear to assume free space propagation. In the simulations, lab tests and field trials, what kinds of propagation environments can be assumed? Can we use, e.g., a sample real-world environment like downtown Norfolk or Boston?

Same answer as previous question.

Question 38: The BAA states that each performer's phase 2 research, analysis and simulation will consider a range of radars and communications systems that are the same across performers. Will those be specified prior to award?

The types of systems to be considered are specified in BAA section 1.1.4.