A Hybrid MAC Protocol with Multi-slot Reservation for Dense Wireless Ad-Hoc Networks

Dense wireless ad-hoc networks (DWAN) is developed with explosive growth of users and traffics, which means that the future network will bear more frequent and intensive communication services under the condition of limited spectrum resource. To meet the requirement of DWAN, an efficient medium access control (MAC) design has been a hot research topic. Towards the current MAC protocols, we mainly focus on addressing two issues in DWAN: (1) serious collisions; (2) low efficiency of spectrum utilization. In this paper, we propose a hybrid MAC with multi-slot reservation for DWAN, called MRPMAC, which is based upon the architecture of the carrier sense multiple access/collision avoidance and time division multiples access. In the proposed MRPMAC protocol, the network collisions are alleviated by using multi-slot reservation (MSR) scheme, and the frequency spectrum efficiency is improved through power control mechanism. Concretely, just with one handshake in the proposed MRPMAC protocol, multiple slots are reserved and multiple concurrent data transmissions are periodically initiated over single channel without collisions. Therefore, spectrum reusing can be achieved, the network throughput is greatly improved as well as quality of service can be ensured in DWAN. Furthermore, the upper bound of slot utilization in MRPMAC is analyzed. Through simulations using ns-2 simulator, we validate that the upper bound of throughput gain brought by power control scheme in MRPMAC is twice as high as pure MSR scheme, and demonstrate that system throughput of MRPMAC outperforms IEEE 802.11 DCF and POWMAC about 150 and , respectively.