## 2 Literature Survey
### Routing Protocols
#### 2.3.3 Destination Sequenced Distance Vector (DSDV) (Table-Driven)  
DSDV is a hop-by-hop distance vector routing protocol. It is a table-driven routing scheme for _Ad hoc_ mobile networks based on the Bellman-Ford algorithm. A routing table listing the \"next hop\" is maintained in each node for the reachable destination. Number of hops to reach destination and the sequence number are assigned by destination node. Each entry in the routing table contains a sequence number used to distinguish older routes from newer ones and thus avoid loop formation. The nodes periodically transmit their routing tables to their immediate neighbors. Routing information is distributed between nodes by sending full dumps infrequently and smaller incremental updates more frequently, so the updating process is both time- and event-driven. DSDV requires a regular update of its routing tables, which uses up battery power and a small amount of bandwidth even when the network is idle. Whenever the topology of the network changes, a new sequence number is necessary before the network re-converges. DSDV is not suitable for highly dynamic networks [20]. Table 1 summarizes a comparison of these routing protocols. \begin{table}
\begin{tabular}{p{42.7 pt} p{85.4 pt} p{85.4 pt} p{85.4 pt} p{85.4 pt}} \hline \hline
**Routing Protocol** & **NODQC** & **AODV** & **OLSR** & **DSDV** \\ \hline Type & Reactive/On-demand & Reactive/On-demand & Proactive/Table driven & Proactive/Table driven \\  & Optimization with & Quick adaptation under & Optimization: MultiPoint & \\  & construct shortest paths & dynamic link & Relays (MPRs) & \\  & within an acceptable & conditions & Forward broadcast & Adds two things to \\  & delay. & Lower transmission & messages during the & distance-vector routing \\  & Lower average end-to-end & Latency & flooding process & Sequence number; \\  & Delay and delay jitter & Consume less network & Only partial link state is distributed & avoid loops \\  & Higher system throughput & bandwidth (less & Optimal routes (in terms of number of hops) & Damping; hold advertisements for changes of short duration \\  & with QoS satisfaction in large networks & Loop-free property & Suitable for large and dense networks & \\  & Scalable to large & Yes & Yes & Yes \\  & networks & Yes & Yes & No \\  & Distributed & Yes & Yes & Yes \\  & Unidirectional & Yes & No & Yes & No \\  & Link Support & & & & \\  & Periodic & Yes & Yes & Yes \\  & Broadcast & Yes & No & Yes & No \\  & Arc weight of link can be determined and & & & & \\  & prioritized & & & & Simplicity \\  & Faster decision making & Lower connection & & Lower route request \\  & Suitable for large and dense networks & Setup time than DSR & & latency, but higher \\  & Construct shortest paths & used for route & & overhead \\  & within an acceptable & freshness and loop prevention & Suitable for large and dense networks & Incremental dumps and settling time used to \\  & Delay. & Maintains only active & Independent from other overhead & reduce control \\  & Lower average end-to-end & routes & protocols & overhead \\  & delay and delay jitter & Uses sequence & & Perform best in \\  & Higher system throughput & numbers to determine & & network with low to \\  & with QoS satisfaction in large networks & route age to prevent & & moderate mobility, few \\  & Low complexity with & usage of stale routes & & nodes and many data \\  & more efficiency and & & & sessions \\  & effectiveness & & & \\  & & & Count-to-infinity problem \\  & Constrains must be & Link break detection & Lack of security & Not efficient for large \\  & relaxed & adds overhead & No support for multicast & Ad hoc networks \\  & Proprietary design & Still have possible & Overhead: maintaining & Routing information is \\  & Applications oriented & latency before data & routes to all nodes is often & Routing information is \\  & Applications oriented & transmission can begin & unnecessary & broadcasted \\  & & & periodically and \\  & & & incrementally \\ \hline \hline \end{tabular}
\end{table}