Available spectrum Market Process –Perceived risk of interference low enough –Pricing (below-equilibrium-price to start with) Regulatory action –Enough 2 nd spectrum to start with –Shared between federal and non-federal users Example: 5G unlicensed band is shared with military radar
Cont’d Current status –FCC rulemaking –Slow in practice, chicken-egg problem –Limited # of players, limited (long-term) guarantees, investment cost –XG: military to military sharing –Unlicensed band can benefit from DSR WLAN that does not interfere with cordless phone WLAN that avoid microwave, bluetooth, etc. Home-networking experience: WLAN, microwave, Bluetooth, cordless phone, sensor networks, etc. A general view: –Smart (heterogeneous) devices work better together, with or without spectrum reforms –Current and future XG: military to military 4G will be an integrated heterogeneous system Integrated WiFi/WiMAX Smart WiFi/mesh
Customer demand (expand) Initial customers –Equipment vendors (WiFi access points with better agility) –Service providers (cellular) On-demand applications –Hotels hosting a convention –Football games –Community networks DIFFERENT QoS (not necessarily worse) –DSR vs. demand-and-control (analogy: Internet vs. telephone nw) –Different properties at different bands, e.g., DSR in VHF band for better penetration –Multimedia services for cellular (not affordable at voice price) –Best-effort service, delay-tolerance service –Or bundle with a band with guaranteed access right (e.g., cellular using extra band through DSR) –Or bundle multiple DSR bands together –If price is right! Legacy applications –Protection, especially with multiple un-coordinated secondaries New applications are often unforeseeable –2.4G was considered as the junk band A lot of these issues are good research topics!
Costs and risks (follow the paper) Costs: –Searching for opportunities, FCC regulations –Spectrum brokers Cooperative DSA –Interference –Trust –Retract access rights by regulators –No guarantee for 2 nd users after demonstration of success business model Non-cooperative DSR –Monitoring, analysis, signaling, cost of mistake –Conservative –Information registry/database: geo location, signature (waveform, pilot), time of operation
Industry structure Spectrum trading –Spectrum aggregating and partitioning –Spatial, temporal, and frequency domain Distributor type 2 as a trusted third party –Install and operate monitoring and analysis systems –Such a monitoring nw may be needed in general –Feasibility and fidelity –How many monitors, where, and how to share information
Notes An interesting paper with related work Papers from a researcher in the area Papers from a conference/special issue An open question/topic focus Update Wiki (reverse chronicle order) First paper is the must read Links for slides? Similar group meeting update at wiki