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– In November/2004, we witnessed the formation of the first worldwide effort to define a novel wireless air interface 1 standard based on Cognitive Radios (CRs): the IEEE 802.22 Working Group (WG). The IEEE 802.22 WG is chartered with the development of a CR-based Wireless Regional Area Network (WRAN) Physical (PHY) and Medium Access Control (MAC) layers(More)
– In November/2004, we witnessed the formation of the first worldwide effort to define a novel wireless air interface (i.e. for use by license-exempt devices in the spectrum that is currently allocated to the Television (TV) service. Since 802.22 is required to reuse the fallow TV spectrum without causing any harmful interference to incumbents (i.e., the TV(More)
Research in the physical (PHY) and medium access control (MAC) layers for dynamic spectrum access (DSA) and dynamic spectrum sharing (DSS) is still at its infancy. Aspects such as spectrum sensing, coexistence, measurement and spectrum management, network reliability and QoS support in face of the need to avoid causing harmful interference into incumbents,(More)
In this paper we address the issue of spectrum sensing in cognitive radio based wireless networks. Spectrum sensing is the key enabler for dynamic spectrum access as it can allow secondary networks to reuse spectrum without causing harmful interference to primary users. Here we propose a set of integrated medium access control (MAC) and physical layer (PHY)(More)
The integration of different technologies with different capabilities and functionalities is an extremely complex task and involves issues at all the layers of the protocol stack. The authors envision an architecture for state-of-the-art heterogeneous multi-hop networks.
Several efforts are now underway to develop wireless technologies based on cognitive radios (CR) that can operate in the television (TV) band white space. One such example is the IEEE 802.22 Working Group (WG), which is formulating the first worldwide CR-based standard to operate in the TV bands. A mandatory requirement for any wireless technology operating(More)
– This paper addresses the issue of deafness and hidden terminal problem in a Mobile Ad Hoc Networks (MANETs) using directional antennas. To minimize these effects, we propose a MAC protocol for directional Antennas (MDA) which employs an enhanced directional network allocation vector (NAV) scheme and, a novel technique of Diametrically Opposite Directions(More)
– This paper addresses the issue of deafness in directional antennas for wireless ad hoc networks. Deafness is caused when a node X repeatedly attempts to communicate with node Y but is unsuccessful, because Y is presently tuned to some other antenna beam. In this paper, we first outline different factors which contribute to such deafness in directional(More)
— Spectrum sensing is essential to the realization of spectrum agility in cognitive radio (CR) networks. Although fundamental tradeoffs and theoretical limits associated with spectrum sensing have been studied extensively, there have been very few experimental studies focused on building a spectrum " sensor " with commercial off-the-shelf devices. We have(More)
10 Abstract 11 Bluetooth is a radio technology for Wireless Personal Area Networking (WPAN) operating in the 2.4 GHz ISM fre-12 quency band, and allows devices to be connected into short-range ad hoc networks. The Bluetooth medium access con-13 trol protocol is based on the Master/Slave paradigm wherein any communication between slave devices has to go 14(More)