Spatial reuse in wireless LAN networks

International audienceThe absence of a radio carrier reuse pattern in wireless LAN systems necessiti- es to apply a collision avoidance mechanism in order to manage all collisions that can produce on the medium sharing. Previous studies concerning cellular radio networks are in general focused on the basis of frequency cell partition- . We re-investigate this frequency reuse topic for wireless LANs where all nodes use the same channel and are randomly placed. Several measurements are presented to compute all radio parameters in a local radio network. Then, theoretical study and simulation results are introduced to deduce the distance that permits a complete carrier reuse by using a carrier sense mechanism

PCF: on exploiting spatial reuse and power conservation opportunities with power control and fairness mechanism for 802.11 WLAN

[[abstract]]Exploiting spatial reuse opportunities allows more parallel transmissions and improve the throughput of wireless networks. Power control is one of the major mechanisms used to exploit both spatial reuse and power conservation opportunities. Increasing the transmitting power prevents the receiver from interference but consume power and create additional interference to other communicating nodes. On the contrary, reducing the transmitting power reduces the interference to other communicating pairs and save sender's power consumption, but result a lower SNR (signal to noise ratio) at receiver side. This article presents power control MAC protocol to exploit the spatial reuse and power conservation opportunities for 802.11 wireless LAN. The proposed protocol evaluates the interference and adopts power control mechanism on both sender and receiver sides, trying to allow more communications proceeding simultaneously. In addition, a fairness control mechanism is also proposed to reduce the average communication delay and alleviate the packet lost phenomenon. Performance results reveal that the proposed protocol improves the throughput and power consumption of WLAN while the fairness among communicating pairs can be maintained.[[conferencetype]]國際[[conferencedate]]20050306~20050308[[booktype]]紙

Exploiting Device-to-Device Communications to Enhance Spatial Reuse for Popular Content Downloading in Directional mmWave Small Cells

With the explosive growth of mobile demand, small cells in millimeter wave (mmWave) bands underlying the macrocell networks have attracted intense interest from both academia and industry. MmWave communications in the 60 GHz band are able to utilize the huge unlicensed bandwidth to provide multiple Gbps transmission rates. In this case, device-to-device (D2D) communications in mmWave bands should be fully exploited due to no interference with the macrocell networks and higher achievable transmission rates. In addition, due to less interference by directional transmission, multiple links including D2D links can be scheduled for concurrent transmissions (spatial reuse). With the popularity of content-based mobile applications, popular content downloading in the small cells needs to be optimized to improve network performance and enhance user experience. In this paper, we develop an efficient scheduling scheme for popular content downloading in mmWave small cells, termed PCDS (popular content downloading scheduling), where both D2D communications in close proximity and concurrent transmissions are exploited to improve transmission efficiency. In PCDS, a transmission path selection algorithm is designed to establish multi-hop transmission paths for users, aiming at better utilization of D2D communications and concurrent transmissions. After transmission path selection, a concurrent transmission scheduling algorithm is designed to maximize the spatial reuse gain. Through extensive simulations under various traffic patterns, we demonstrate PCDS achieves near-optimal performance in terms of delay and throughput, and also superior performance compared with other existing protocols, especially under heavy load.Comment: 12 pages, to appear in IEEE Transactions on Vehicular Technolog