MIMO-Aware Routing in Wireless Mesh Networks

Abstract

Abstract-Multiple-input and multiple-output (MIMO) technique is considered as one of the most promising emerging wireless technologies that can significantly improve transmission capacity and reliability in wireless mesh networks. While MIMO has been widely studied for single link transmission scenarios in physical layer as well as from MAC perspective, its impact on network layer, especially its interaction with routing has not drawn enough research attention. In this paper, we investigate the problem of routing in MIMO-based wireless mesh networks. We mathematically formulate the MIMO-enabled multi-source multidestination multi-hop routing problem into a multi-commodity flow problem by identifying the specific opportunities and constraints brought by MIMO transmissions, in order to provide the fundamental basis for MIMO-aware routing design. We then use this formulation to develop a polynomial time approximation solution that maximizes the scaling factor for the concurrent flows in the network. Moreover, we also consider a more practical case where controllers are distributed, and propose a distributed algorithm to minimize the congestion in the network links based on steepest descent framework, which is proved to provide a fixed approximation ratio. The performance of the algorithms is evaluated through simulations and demonstrated to outperform the counterpart strategies without considering MIMO features.

Routing, spectrum access, and scheduling in multi-hop multi-channel wireless networks with MIMO links

“…In [23], the authors defined a joint optimization problem of bandwidth allocation, element assignment, and scheduling without assuming the same number of antenna elements on each WMN node and also proposed a technique to minimize the total number of the antenna elements. MIMO-aware routing and joint design of routing, scheduling, and stream control to obtain optimal throughput for single-channel multi-antenna WMNs have been studied in [5][6][7][8]. However, dynamic channel assignment and sharing as well as its benefits and constraints are not considered in those studies.…”

“…(i) To properly configure the encoding and decoding vectors, both transmitter and receiver should be aware of the instantaneous channel coefficient matrices. This is a common assumption for many higher layer algorithm designs [5][6][7][8][9][10]. However, even without such an assumption, there exist practical estimation techniques that have already been applied in implementations and given fairly good results [25].…”

“…Most existing studies on applying MIMO technique in wireless mesh networks focus on single-channel WMNs [2][3][4][5][6][7][8]. Channel assignment is not an issue for those cases.…”

Link Scheduling for Exploiting Spatial Reuse in Multihop MIMO Networks

“…In multi-hop MIMO networks [5], some efforts have been made in recent years on developing MAC and routing protocols, e.g., [6], [7], [8], [9]. In such a setting, MIMO enhances the potential network throughput via spatial multiplexing by achieving high data rates or spatial reuse of the spectrum by allowing multiple simultaneous communications at the same vicinity.…”

Joint routing, scheduling and power control in multihop MIMO networks with MAC and broadcast links

“…Throughput optimization problems with simpler phy layer modeling are considered in [11], [2]. Routing in multihop wireless networks with MIMO is considered in [4]. In [17], a simple phy layer model is provided and used with zero forcing beam-forming.…”