A Survey of Routing Protocols that Support QoS in Mobile Ad Hoc Networks <s> Resource Reservation <s> We present the design, implementation, and evaluation of INSIGNIA, an IP-based quality of service framework that supports adaptive services in mobile ad hoc networks. The framework is based on an in-band signaling and soft-state resource management approach that is well suited to supporting mobility and end-to-end quality of service in highly dynamic environments where the network topology, node connectivity, and end-to-end quality of service are time varying. Architecturally INSIGNIA is designed to support fast reservation, restoration, and end-to-end adaptation based on the inherent flexibility and robustness and scalability found in IP networks. We evaluate the framework, paying particular attention to the performance of the in-band signaling system, which helps counter time-varying network dynamics in support of the delivery of adaptive services. Our results show the benefit of our framework under diverse mobility, traffic, and channel conditions. <s> BIB001 </s> A Survey of Routing Protocols that Support QoS in Mobile Ad Hoc Networks <s> Resource Reservation <s> This specification discloses a building structure including a structural member comprising a web, two flanges projecting from opposite edges of the web and inturned lips at the free edges of the flanges; electrical wiring laid in a channel defined by one of the flanges, its inturned lip and the portion of the web adjacent to said flange; and a U-section cover member having limbs which interfit with said lip and said portion of the web and a base which extends over the mouth of the channel thus protecting the wiring. <s> BIB002
One difference between regular routing protocols and QoSaware routing protocols is that QoS-aware routing requires some form of resource reservation. TDR uses temporary reservation of bandwidth during route discovery and updates the reservation upon receiving a route deactivation packet. Also, the reserved bandwidth is updated in a fixed soft-state interval. Temporary reservation is a one time action, but the soft state is updated periodically by the in-session data. AQOR also uses a temporary reservation mechanism to eliminate the connection tear-down process along the old route when the route is adjusted. One unique feature of AQOR is that QoS violations are detected at the destination, prompting destination-initiated route recovery. ADQR uses a QoS_Reserve packet to reserve bandwidth from the source to the destination. CEDAR does not explicitly describe the signaling approach used, but it assumes the existence of some instantaneous reservation mechanism. Ticket-based QoS routing uses a confirmation message to lock the established route after the primary route is selected. OLSR-based QoS routing and BEQR do not incorporate any explicit reservation schemes. Resource Reservation Protocol (RSVP)-type signaling BIB002 , used extensively in wired networks, requires a large amount of overhead and thus is not directly suitable for MANETs. An in-band signaling technique for MANETs has been proposed in BIB001 and shown to work well in MANETs. Thus, the third open issue in QoS-aware routing is: how should in-band signaling be coupled with the routing protocol for resource reservation? The following ideas were proposed to minimize overhead exchange for resource reservation. • Soft-state reservations: nodes use the active data transmission to reserve the corresponding bandwidth. • Temporary reservations: the bandwidth is reserved only for a certain interval and if no data packets are received for a certain time, the reservation is automatically released. • Destination-initiated recovery: the destination initiates a routing request procedure when a QoS violation is found. • Signal strength triggered reroute: Using received signal strength to predict link breaks (and hence route breaks)  , a host prepares to reroute data when the received signal strength falls below a threshold, and it reroutes the data as the signal strength further deteriorates. Therefore, the data is rerouted through a new route that can support the QoS requirements before the route breaks, reducing the transmission break time and avoiding sending packets along a route that soon will be broken. • Route redundancy: In this approach, hosts maintain secondary routes to use when the primary route fails. However, there is a trade-off between route redundancy and overhead. • Other proposed schemes for rerouting data: Some protocols use route re-computation at the failure point when a link failure occurs near the destination and route re-computation at the source when a link failure occurs near the source. Destination triggered rerouting and neighbor loss detection triggered rerouting also are used in some protocols. Each of these techniques requires extra overhead, and thus it is not obvious which one(s) will provide benefit in QoS performance for different network scenarios.