A MAC Protocol for Multihop RP-CDMA Ad Hoc Wireless Networks

Abstract

RP-CDMA is a wireless multiple access technique that utilizes multiple spreading codes and a multiuser detector to enhance link reliability and performance. We propose a simple MAC protocol on top of the RP-CDMA Phy and apply it to the multihop ad hoc network model. In addition to a MAC, we propose two significant extensions to RP-CDMA aimed at improving throughput and reliability. We test our network device using the ns-3 network simulator and compare its performance to that of the well known 802.11 CSMA model. Our simulations confirm that RP-CDMA can substantially improve link reliability and network performance, but that a link level acknowledgement mechanism is required to ensure packet delivery across the network. We investigate a simple acknowledgement policy and conclude that it enables simultaneous high throughput and packet delivery while maintaining low latency.