Wi-Fi Mesh

The WNL team has accumulated extensive experience in the study of multi-hop wireless self-organizing networks (MWSONs), commonly known as mesh networks and MANETs (Mobile Ad hoc Networks). Within a number of projects, analytical models of IEEE 802.11s network operation were developed for the first time, taking into account the imperfections of the random multiple access mechanism and the problem of flow self-interference. A key result was the identification of the causes of uneven throughput distribution among connections, which was later confirmed experimentally.

A special place in our research portfolio is occupied by studies of the deterministic channel access mechanism (MCCA). We not only identified the shortcomings of MCCA (in particular, low transmission reliability under interference), but also, for the first time, developed mathematical models for constant-bit-rate multimedia traffic transmission using channel reservation. The developed queueing system models with retransmissions and “impatient” requests made it possible to calculate the minimum amount of resources required to guarantee QoS requirements in terms of packet loss ratio and delay.

In the field of network protocols, we conducted an in-depth analysis of routing metrics. We demonstrated the inadequacy of using a single metric in heterogeneous IEEE 802.11s environments. For the first time, we substantiated the necessity of multi-metric routing that takes into account the traffic class (unicast/multicast) and the channel access mechanism. Original route selection algorithms for reliable multicast dissemination were proposed and investigated.

A critically important result is the development of theoretical foundations for link management in mobile mesh networks. The proposed algorithms make it possible to discard unstable links already at the neighbor discovery stage, which significantly increases route stability. This work was awarded the Best Paper Award at the prestigious IEEE ISWCS 2012 international conference (Paris), and further development of this research direction was supported by a Student Grant at IFIP Wireless Days 2012 (Dublin).

A substantial part of the work was carried out using the advanced ns-3 simulation environment. The team from the Institute for Information Transmission Problems (IITP RAS) developed and integrated into the open-source ns-3 framework a detailed model of the Wi-Fi Mesh protocol stack (IEEE 802.11s), including implementations of both random access mechanisms (EDCA) and deterministic access (MCCA). This made it possible not only to validate our analytical models but also to provide the global research community with a powerful tool for further studies.

The team actively participated in the European Union FLAVIA project (FP7) from 2010 to 2013, being responsible for the distributed medium access control block. The results were highly appreciated by experts of the European Commission. In addition, research was conducted within the CELTIC PLUS project “Survivable Ad hoc Network for 4G and beyond,” where the team contributed to the development of multi-hop network architectures based on 4G technologies and future wireless systems.

The accumulated research has been validated not only in academic settings but also under the stringent requirements of industrial customers. In collaboration with a Russian company, the unicast and multicast routing protocols for mobile mesh networks developed by our team demonstrated multiple-fold superiority over existing commercial solutions in terms of performance and robustness to network topology dynamics.

List of relevant papers: