**2.3.1 AODV (Ad-Hoc On-demand Distance Vector routing)**

This protocol can be regarded as an improvement of DSDV. AODV minimises the number of distributions by creating routes on-demand [Esmaili. H et al, 2011]. In contrast, DSDV maintained a list of all routes to find a route to the destination whenever the origin broadcasts a route request packet to all nodes. The neighbours distribute the packets among their neighbours until the packet reaches an intermediate node with a new route to the destination [Song J. H et al, 2004].

Energy Consumption Analysis of Routing Protocols in Mobile Ad Hoc Networks 255

Figure 7 (a) shows how the route demand packet is distributed in the network and indicates its route record section [Perkins E, 2008]. If the destination node produces a reply on each route, this node places the route record section of the route demand packet in the route reply [Suresh A et al 2011]. In another state, if an intermediate node wants to produce a route reply, it will place its cached route to the destination in the route record section of the route demand packet. Figure 7 (b) indicates the state in which the destination node itself has

sent a route reply [Qun Z. A et al 2011].

(a)Distribution of demand packets

Fig. 7. An instance of route detection in DSR

**2.3.3 TORA protocol (Temporally-Ordered Routing Algorithm)** 

The main characteristic of TORA is the centralization of control messages in a very small set of near local nodes in which topological changes have been made. To achieve this property, nodes maintain routing information for the adjacent nodes for some interval. This protocol has three duties: route formation, route renovation and route cleaning. Route formation is performed with QRY\* and UPD† [Park. V et al 2001]. A route formation algorithm starts by determining a zero set for height of destination node and empty set for height of other

(b)Reply packets

nodes. 

\*Query protocol †User Datagram Protocol

Figure 6 (a) indicates a distribution packet among neighbors. If a node saw the packet previously, it will discard it and will not pay attention to it. Route demand packet uses sequence numbers in order to ensure that a ring is not formed in the route [Bai F et al, 2004]. This mechanism also guarantees that if intermediate nodes reply to this request, it will be based on their latest information. AODV uses only symmetric and two-sided links because routing the reply packet is achieved by simply reversing the packet route. Figure 2. 3 (b) shows the process of reply to demand [Bamis. A et al, 2008].

(a)Distribution packet among neighbors

(b) Reply to demand

Fig. 6. Detection of route in AODV

### **2.3.2 DSR (Dynamic Source Routing protocol)**

The Dynamic Source Routing protocol (DSR) is a simple and efficient routing protocol designed specifically for use in multi-hop wireless ad hoc networks of mobile nodes. DSR allows the network to be completely self-organising and self-configuring, without the need for any existing network infrastructure or administration. The protocol is composed of two main mechanisms - "route discovery" and "route maintenance" - that work together to allow nodes to discover and maintain routes to arbitrary destinations in the ad hoc network [Suresh A. et al, 2011].

Figure 7 (a) shows how the route demand packet is distributed in the network and indicates its route record section [Perkins E, 2008]. If the destination node produces a reply on each route, this node places the route record section of the route demand packet in the route reply [Suresh A et al 2011]. In another state, if an intermediate node wants to produce a route reply, it will place its cached route to the destination in the route record section of the route demand packet. Figure 7 (b) indicates the state in which the destination node itself has sent a route reply [Qun Z. A et al 2011].

(a)Distribution of demand packets

(b)Reply packets

254 Real-Time Systems, Architecture, Scheduling, and Application

Figure 6 (a) indicates a distribution packet among neighbors. If a node saw the packet previously, it will discard it and will not pay attention to it. Route demand packet uses sequence numbers in order to ensure that a ring is not formed in the route [Bai F et al, 2004]. This mechanism also guarantees that if intermediate nodes reply to this request, it will be based on their latest information. AODV uses only symmetric and two-sided links because routing the reply packet is achieved by simply reversing the packet route. Figure 2. 3 (b)

shows the process of reply to demand [Bamis. A et al, 2008].

(a)Distribution packet among neighbors

(b) Reply to demand

[Suresh A. et al, 2011].

Fig. 6. Detection of route in AODV

**2.3.2 DSR (Dynamic Source Routing protocol)** 

The Dynamic Source Routing protocol (DSR) is a simple and efficient routing protocol designed specifically for use in multi-hop wireless ad hoc networks of mobile nodes. DSR allows the network to be completely self-organising and self-configuring, without the need for any existing network infrastructure or administration. The protocol is composed of two main mechanisms - "route discovery" and "route maintenance" - that work together to allow nodes to discover and maintain routes to arbitrary destinations in the ad hoc network Fig. 7. An instance of route detection in DSR
