Capacity and Coverage Analysis of Rural Multi- Radio Multi-hop Network Deployment using IEEE802.11n Radios Alvin Ting, David Chieng and Kae Hsiang Kwong Wireless Communications MIMOS Berhad Kuala Lumpur, Malaysia {kee.ting,ht.chieng,kh.kwong}@mimos.my Abstract— This paper presents the capacity and coverage performance analysis of a multiradio multihop network deployment using IEEE802.11n radios for a typical rural area in Malaysia. Insights on the relationships between various key design parameters particularly backhaul link rate, backhaul link distance/multihop distance, coverage size per MAR/total coverage size, number of MIMO spatial multiplex (SM) stream, number of MAR per branch and effective capacity per access point or per user are acquired. Two optimization objectives namely 1) to maximize coverage size and 2) to maximize backhaul distance are introduced. Keywords-component; Wireless Mesh/Multihop Network; Rural Deployment; IEEE 802.11n; Backhaul I. INTRODUCTION Accelerating broadband penetration and bridging the digital divide between rural and urban communities have long been one of the main agenda of governments worldwide. Over the years, various initiatives have been launched in Malaysia to provide Internet access to the rural communities. More recently Ministry of Information, Communications and Culture and the Malaysian Communications and Multimedia Commission launched the “Kampung WiFi” initiative [1], which aims to accelerate the national broadband penetration at the rural areas. According to NBI, the broadband access in rural areas shall include Basic Telephony Access (via fixed and mobile networks), broadband connected Community Broadband Libraries (CBLs) and Community Broadband Centres (CBCs). Motivated by the lacked of wired infrastructure in these areas, Wireless Mesh Network (WMN) has become a highly promising means to provide broadband access. As for the radio technology, IEEE802.11 WLAN or WiFi is naturally preferred due to cost factor and wide spread market adoption. Over the years WMN technologies, particularly those based on WiFi radios, have evolved from single radio systems to multiradio systems involving heterogeneous radio interfaces such as IEEE802.11a, b, g and n. The most commonly known industrial practice adopts the architecture which comprises of IEEE802.11a radios at the backhaul and IEEE802.11g for the access. This is largely motivated by the fact that IEEE802.11a has more non overlapping channels and much less congested spectrum band. Although WMN offers a wide range of benefits, it continues to suffer capacity limitation due to excessive sharing of capacity as the number of hop increases. To this end the recently approved IEEE 802.11n standard which offers physical data rates up to 600Mbit/s and higher resiliency towards interference via MIMO technology may change the perception to a certain extent. To date there are already a wide range of 11n-based wireless mesh/multihop network products and solutions in the market. However, the performance of such network is not well understood especially from the capacity and range (coverage) viewpoints. In particular this paper aims to understand the relationships between various key design parameters such as backhaul link rate, backhaul link distance/multihop distance, coverage size per MAR/total coverage size, number of MIMO spatial multiplex (SM) stream, number of MAR per branch and effective capacity per access point which can later be translated into data rate per user using IEEE802.11n radios. The study takes into consideration the unique characteristics in rural deployments, i.e. distribution of the users is rather concentrated like a hotspot but distributed. Unlike the urban case, the distance between hotspots may range from hundreds of meter to tens of km (between villages). Also unlike the urban zones, contiguous coverage is not required. Fig. 1 provides a snapshot of a typical rural deployment in Malaysia. Figure 1. Case Study: Kampung (village) Ulu Dusun , Sabah, Malaysia.*courtesy of Google Maps. We first, we developed an analytical model that includes physical layer, mac layer and propagation model to evaluate the capacity and coverage for a multi-radio multihop infrastructure network.. In this model, access radio and Branch 2 Branch 1 Branch 3 2011 IEEE 10th Malaysia International Conference on Communications (MICC) 2nd – 5th October 2011 | Sutera Harbour Resort, Kota Kinabalu, Sabah, Malaysia 978-1-4577-0978-4/11/$26.00 ©2011 IEEE 77