V. S. Eremin, P. V. Prokhorov
Mesh network – a number of nodes, connected in a computer network by wireless communication channels.
Mesh network has the following features:
• Shared data transfer medium;
• Initially it is a peer-to-peer network;
• Network is self-configurating;
• Each node is a router;
• Network topology may change in time;
• New nodes can connect to existing network.
Any node has at least one wireless network interface. In addition a node can have a wired or wireless interface, or additional radio interfaces at different frequency ranges.
The advantages of self-configuring networks are:
• Either increasing network coverage without increasing the power of radio equipment or reduction of power of radio equipment, while maintaining the initial coverage;
• Reducing the cost of network management (frequency resource planning, address space, setting up ways to enter the global or corporate network, etc.).
Nevertheless Mesh network technology has imperfections due to its features.
Failover network requires active connection in case of one or more nodes' failure . So each network node has to analyze the quality of the communication channel according to a dynamic routing table, which shows changes in network topology.
The route search is not an easy matter. To solve this problem the shortest path algorithms are applied. The route is chosen between variations of minimum cost criterion. The calculation takes into account the bandwidth of each relay station and the entire route from beginning to end. Also, the time of packet delivery, which is one of the main parameters of communication networks for real-time traffic (voice and video communications), is taken into account.
The required transmitter power increases exponentially with increasing distance from the receiver. Application of Mesh technology allows reducing the required power of transmitting devices. Thus, the introduction of additional retransmitting nodes reduces the required output power of transmitter. This is significant advantage in terms of communication devices licensing and certification.
Any system has vulnerabilities and Mesh technology is not an exception from this rule. Mesh nodes can not be considered safe in general. Data can be substituted by transmitting nodes because retransmitting node has full access to this data. Sending confidential data in clear text is unacceptable.
Each node participating in routing must provide a specific set of services such as forwarding, service data routing, connected and disconnected nodes watch, traffic shaping in accordance with the established quality of service. Also node must not block all network bandwidth by its sole traffic. The result of violations of these prohibitions is network overload, denial of service that is fully reflected in the quality of the connection.
The way of resistance to such abuses is to block nodes, which violate these rules. An effective way to impact on such a node is to exclude it from the routing.
In this situation the node will be removed from the network and further interaction with him will be impossible. This method of protection is active against the attacker node on the link layer, but does not allow resisting to nodes, which create conflicts in the communication channel.
Mesh networking technology has a high potential for creating new networks with a high level of reliability, quality and network bandwidth.