The International Dynamic Spectrum Access Networks (DySPAN) symposium has emerged as the preeminent event to gather international economists, engineers, network architects, researchers and academic scholars together to share cutting edge research on and demonstrations of emerging wireless technology. DySPAN has since 2005 had a major influence on policy and technology research and development in the United States, Europe and Asia. The following bullets summarizes my key takeaways from DySPAN 2011:
- Much focus was on TV White Spaces (TVWS). Studies on available TVWS channels in different regions was presented, and there seems to be a lot. The correctness of TVWS database estimations with different path loss models was presented by Ranveer Chandra from Microsoft by comparing with sensing results. None of the path models tested gave false positives, thought the accurateness of the path loss model is crucial for maximizing spectrum utilization. Furthermore, Victor Bahl from Microsoft also presented their TVWS network trials. Bahl stated that Microsoft and Google are enemies when it comes to search, but they are in bed together when it comes to TVWS because both want to provide connectivity to everyone to best extent possible. Overall, TVWS seems to be accepted by the DySPAN community.
- Douglas Sicker from FCC presented the Spectrum Dashboard which also can be considered a tool to find available spectrum bands in the US. He also emphasized the importance of internationalization and encouraged a global market for dynamic spectrum access. He sends the message to DySPAN to work on this issue.
- David Cleevely presented analysis of the value per MHz versus technology and concluded that unlicensed spectrum generates more value than licensed spectrum! Furthermore, he concludes that femtocells will revolutionize the mobile industry.
- Krishan Sabnani from Bell Labs talked about spectrum virtualization and that a spectrum server is the final thing. He wants to use practices from virtualization in data computing. Base stations can be virtualized and run in the cloud.
- Pierre De Vries presented a paper where he propose that operating rights should be articulated using transmission permissions and reception protections, defined probabilistically (the Three Ps). Such a policy would remove the zero tolerance of interference limit violation and ease the introduction of dynamic spectrum access.
- Martin Weiss presented a paper where he focuses on the importance for the emergent regulatory policies to explicitly consider the requirements of secondary users, which not has been done yet because the secondary users not exists in meaningful number nor does they have any clear application. Furthermore he proposes to address this by explicitly consider the impact of the spatiotemporal properties of spectrum holes on the use decision by potential secondary users.
- Mitola is worried about commercializing the white space databases since he doubts that we can trust the commercial sector?
- In a panel about business perspectives on dynamic spectrum access, the urge of testbeds on white spaces was stressed by many. From an operators perspective Berna Sayrac from France Telecom mention that cognitive radio is much more than dynamic and opportunistic spectrum access, but that it can be used to manage our spectrum more efficiently. From a vendor perspective Lasse Wieweg from Ericsson mention that the most important for them is economy of scale, hence spectrum should be harmonized and he would like to see regulators worldwide to agree with each other and coordinate. He also states: do not be afraid of the higher bands such as 3.5 and 4.2 GHz.