Dynamic Spectrum Access

Dynamic Spectrum Sharing

The evolution of wireless communication services and technologies increasingly relies on efficient methods for sharing the electromagnetic (radio-frequency) spectrum in order to enable heterogeneous devices and applications to coexist harmoniously. Prototyping and experimentation is an important step towards the transition-to-practice of the extensive research in the field of Dynamic Spectrum Access (DSA). COSMOS provides the infrastructure needed for DSA experimentation. COSMOS is located within an Innovation Zone created by the FCC to facilitate research and testing, and it provides a large number of radio nodes, computation nodes, and optical communication infrastructure that allows for experimentation with diverse DSA methods (e.g., cooperative or non-cooperative) and architectures (e.g., centralized or distributed). The New York City (NYC) dense urban environment is a stressful case for spectrum sharing. Techniques validated using these scenarios in an urban testbed are expected to function well in other cities as well as in less-dense environments.

Motivated by DARPA’s efforts on the Spectrum Collaboration Challenge (SC2) and the recent “IEEE 1900.5.2: Standard method for modeling spectrum consumption” we are conducting research on cooperative DSA methods that leverage Spectrum Consumption Models (SCMs). SCMs offer a standardized mechanism for RF devices to declare their intention to use the spectrum (in the case of transmitters) or their needs in terms of spectrum protection  (in the case of receivers and passive devices). This declaration (i.e., the SCM) can simplify spectrum use coordination when compared to DSA algorithms that rely solely on sensing to avoid interference between several RF transmitters and receivers. In [1], we developed a simple framework on COSMOS that performed DSA coordination automatically using SCMs. Specifically, as shown in Fig. 1, when radios enter the network they receive SCMs from existing devices and then perform Compatibility Tests (CTs) in order to determine available spectrum bands for utilization. A video describing this mechanism in detail can be found below.

Figure 1 – (a) A spectrum deconfliction algorithm. (b) An example of deconfliction with three radio links
Figure 1 – (a) A spectrum deconfliction algorithm. (b) An example of deconfliction with three radio links [1].

In [2], we developed a novel SCM-based DSA mechanism that takes into consideration aggregate interference and makes use of frequency and power adjustments to deconflict spectrum use. We built a custom simulation platform to evaluate the algorithm’s performance, scalability, and feasibility in dynamic and dense communication environments. We plan to prototype and test this DSA mechanism on COSMOS soon.

A project funded in Dec. 2022 by an NSF grant from the Spectrum Innovation Initiative: National Radio Dynamic Zones (SII-NRDZ) program will expand on the efforts above and investigate and prototype a management system for spectrum sharing in NYC.

References:

[1] D. Stojadinovic, P. Netalkar, C. Bastidas, I. Kadota, G. Zussman, I. Seskar, and D. Raychaudhuri, “A Spectrum Consumption Model-based Framework for DSA Experimentation on the COSMOS Testbed,” in Proc. ACM MobiCom’21 Workshop on Wireless Network Testbeds, Experimental evaluation & CHaracterization (WiNTECH), 2021. [download] [presentation] [video]

[2] P. Netalkar, A. Zahabee, C. Bastidas, I. Kadota, D. Stojadinovic, G. Zussman, I. Seskar, and D. Raychaudhuri, “Large-Scale Dynamic Spectrum Access with IEEE 1900.5.2 Spectrum Consumption Models,” in Proc. of IEEE WCNC’23 (to appear), 2023. [download]