rgy savings. In Routing Boundary Aware of Tasks a multiple short hop-routing algorithm with power Policy Deployment management just closing the wireless link with multiple short hops is usually more energy efficient than one long Figure 2.4b-6 CR use case for geolocation. Several interactions between the CR and the world are enabled or required by hop. Knowing the position of each node in a potential geolocation information. route allows the CR to take energy consumption into consideration when routing a packet. Spatially variant searching is a powerful concept for Information Theory and Computer Science Interface increasing a user's operating efficiency. If it is time for workshops that communicate CR research results. supper, the CR may begin a search for the types of res- The SDR Forum has a CR Working Group that is in- taurants the user frequents and sort them by distance and vestigating various CR technologies such as spectrum popularity. Other spatially variant searches are possible. access techniques, and a Cognitive Applications Special A radio aware of boundaries may be able to invoke Interest Group that is working with regulatory bodies, policy as a function of geopolitical region. When passing spectrum owners, and users to communicate the poten- from one regulatory jurisdiction to another, the rules tial of CR technologies. Numerous organizations partic- change. The radio can adopt a conservative operation ipate at SDR Forum meetings. It is expected that the mode near the boundaries and change when they are SDR Forum will solicit inputs from industry through crossed. The radio must have the ability to distinguish one a Request for Information (RFI) process in the near region from another. This may require a database (which future. must be kept up-to-date) or some network connectivity Both the Federal Communications Commission with a boundary server. Figure 2.4b-7 shows a simplified (FCC) and the National Telecommunications and In- sequence diagram in which a CR accesses spectrum as formation Administra