16.2 MANETs ROUTING APPROACHES
There are two general categories of MANET routing protocols: topology-based and position-based routing protocols. We present a brief overview of each group. Before proceeding, it is fitting to list some desirable qualitative properties of MANET routing protocols. This list is adopted from an Internet Engineering Task Force (IETF) MANET Working Group memo .
- Loop-free: It is desirable that routing protocols prevent packets from circling around in a network for arbitrary time periods.
- Demand-based operation: In order to utilize network energy and bandwidth more efficiently, it is desirable that MANET routing algorithms adapt to the network traffic pattern on a demand or need basis rather than maintaining routing between all nodes at all time.
- Proactive operation: This is the flip-side of demand-based operation. In cases where the additional latency—which demand-based operations incur—may be unacceptable, if there are adequate bandwidth and energy resources, proactive operations may be desirable in these situations.
- “Sleep” period operation: It may be necessary—for reasons such as the need for energy conservation—for nodes to stop transmitting or receiving signals for arbitrary time periods. Routing protocols should be able to accommodate sleep periods without adverse consequences.
- Security: It is desirable that routing protocols provide security mechanisms to prohibit disruption or modification of the protocol operations.
16.2.1 Position-Based Routing ...