## 2 Related Work  
Routing is the process of selecting the best path or paths in a network through which data will be forwarded. Forwarding paths are not necessarily the shortest ones and are selected usually seeking to improve the service performance. Proposals of routing protocols for ad hoc networks similar to our work can be classified in four categories: (a) single path routing; (b) general multipath routing; (c) multipath routing used to transmit video; and (d) game-theoretical algorithms used in the routing. In the following we summarize some representative works related to our proposal for each category. 1. Regarding single path routing, many protocols were designed in the last years for MANETs [4; 5; 6; 7; 8; 9; 10] based on improvements of basic and widely referenced ad hoc routing protocols such as ad hoc on-demand distance vector (AODV) [11] and dynamic source routing (DSR) [12]. Based on AODV, [4] incorporates an admission control scheme and a feedback scheme to satisfy the QoS-requirements of real-time applications; [5] adds a route fragility coefficient (RFC) as a metric to find stable routes; [6] proposes an efficient algorithm to balance energy consumption among all participating nodes; and [7] provides \(n\) backup routes in case of link failure instead of one. On the other side, based on DSR, [8] presents a pragmatic scheme to establish and sustain trustworthy routes in the network; [9] introduces a new route maintenance strategy called distance based route maintenance (DISTANCE) to prevent link failure; and [10] uses the ant colony optimization (ACO) algorithm producing a significantly improvement in terms of packet losses, end-to-end delay, routing overhead and energy consumption. 2. Some works like [13, 14, 15, 16, 17] tackle the congestion problem present when the MANET is heavily loaded, since this factor negatively affects the packet losses. To cope with this issue, multipath routing protocols were proposed to alleviate congestion, optimize the use of the scarce MANET resources, increase the packet delivery ratio and improve the offered quality of service. For example, authors in [13] proposed the congestion-adaptive routing protocol (CRP) to prevent congestion. Simulation results show that CRP improves significantly the packet loss rate and the end-to-end delay compared to AODV and DSR. In [14], the authors introduced a type of service aware routing protocol (TSA) which uses both the packet type of service and the traditional hop count as route selection metrics. This proposal tries to avoid congestion by distributing the load over a potentially greater area. A linear load balancing protocol using multiple paths is proposed in [15], where \(n\) routes are sorted in increasing order of their hop count and have assigned priority values so that the shorter the path the higher the priority of the path to be selected to distribute the transmitted packets. In [16], the authors introduced a mechanism to find a primary forwarding route using the basic AODV engine and an alternative backup path to be used when the main route is broken. The backup path excludes nodes already used in the primary path, so that they are node-disjoint paths. The work [17] presented the Fibonacci multipath load balancing protocol (FMLB) for MANETs to distribute transmitted packets over multiple paths through the mobile nodes using an algorithm based on the Fibonacci sequence. 3. Multipath routing protocols offer interesting benefits to increase the available bandwidth, which is suitable to transmit video over ad hoc networks where the bandwidth is a scarce resource. Several works such as [18, 19, 20, 21, 22] presented interesting approaches to transmit video flows over multipath frameworks. In [18], the authors analyzed the topic of multipath routing for multiple description video coding in wireless ad hoc networks. They found that genetic algorithms (GAs) are effective to address this type of cross-layer optimization problems. They demonstrate using numerical results the superior performance of their GA-based approach.