| The Army is transforming its tactical communications architecture addressing the lack of bandwidth for data, voice and video applications and the inability to communicate on-the-move (OTM) in non-line of sight (NLOS) environments identified in past operations. A critical operational requirement of the Army’s Future Tactical Network (FTN) is the capability of mobile mesh networking, commonly called Mobile Ad-Hoc Networks (MANET). The IEEE 802.16d standard, known as Fixed WiMax, is an emerging broadband wireless access (BWA) technology the Army is investigating as a potential commercial-off-the-shelf (COTS) solution. This paper evaluates the Mesh Mode defined in the Fixed WiMax standard to determine if it is technically feasible for WiMax to support mobile mesh networks by: 1) restricting the Mesh Mode to distributed scheduling, 2) replacing the Mesh Mode OFDM physical layer (PHY) profile with a SOFDMA PHY profile defined in the 802.16e (Mobile WiMax) standard, and 3) organizing the network into clusters, interconnected by a scalable MANET routing protocol. This paper considers the Army’s FTN requirements in terms of range,throughput and mobility as specified in the Warrior Information Network – Tactical (WIN-T) and Future Combat Systems (FCS)requirements documents operating at a 1500 MHz frequency band. These requirements serve as a benchmark which analytical analysis of the proposed Mesh Mode adaptations will be compared. From this comparison a recommendation is made to the technical feasibility of WiMax supporting a COTS solution for tactical mobile mesh communications. This paper also includes results of a mobility experiment using Fixed WiMax equipment. The experiment evaluated throughput, latency and multimedia streaming capability of a CPE traveling at 45 mph. Results suggests an OFDM physical layer is capable of supporting mobile nodes despite the slowness of the adaptive modulation algorithm. Findings warrant further research in integrating a meshing capability with existing WiMax standards. |