In Figure 1, the nodes A—F are interior nodes, As seen, proactive routing uses excess bandwidth to maintain the nodes G—J are peripheral nodes and the node K is outside routing information, while reactive routing involves long the routing zone. Note that node H can be reached by two route request delays. Reactive routing also inefficiently floods paths, one with length 2 and one with length 3 hops. When the packet reaches the destination, the sequence The globally reactive routing component is named Inter-zone of addresses is reversed and copied to the route reply packet.
Instead, IARP is a family of limited-depth, In the second case, the forwarding nodes records routing proactive link-state routing protocols. IARP maintains routing information as next-hop addresses, which are used when the information for nodes that are within the routing zone of the reply is sent to the source.
This approach can save node. Correspondingly, IERP is a family of reactive routing transmission resources, as the request and reply packets are protocols that offer enhanced route discovery and route smaller. Alternatively, the nodes along the path to by IARP.
Instead of broadcasting packets, ZRP uses a concept the destination record the next-hop address in their routing called bordercasting. Bordercasting utilizes the topology table.
The bordercast packet delivery service is This type of one-to-many transmission can be implemented as provided by the Bordercast Resolution Protocol BRP. BRP multicast to reduce resource usage. One approach is to let the uses a map of an extended routing zone to construct bordercast source compute the multicast tree and attach routing trees for the query packets.
Alternatively, it uses source instructions to the packet. This is called Root-Directed routing based on the normal routing zone. By employing Bordercasting RDB. Another approach is to reconstruct the query control mechanisms, route requests can be tree at each node, whereas the routing instructions can be directed away from areas of the network that already have omitted. This requires that every interior node knows the been covered. In order to detect new neighbor nodes and link topology seen by the bordercasting node.
Upon receiving a beacon, the neighbor table is updated. Neighbors, named Distributed Bordercasting DB. If a zone radius of one hop is used, routing is purely The relationship between the components is illustrated in reactive and bordercasting degenerates into flood searching.
If Figure 2. Route updates are triggered by NDP, which notifies the radius approaches infinity, routing is reactive.
The IARP when the neighbor table is updated. BRP uses the routing table of the view of the zone. Route maintenance Routing Route maintenance is especially important in ad-hoc A node that has a packet to send first checks whether the networks, where links are broken and established as nodes destination is within its local zone using information provided move relatively to each other with limited radio coverage.
In by IARP. In that case, the packet can be routed proactively. Until the new route is available, packets are The reactive routing process is divided into two phases: the dropped or delayed. In the route In ZRP, the knowledge of the local topology can be used for request, the source sends a route request packet to its route maintenance.
Link failures and sub-optimal route peripheral nodes using BRP. If the receiver of a route request segments within one zone can be bypassed. Incoming packets packet knows the destination, it responds by sending a route can be directed around the broken link through an active reply back to the source.
Otherwise, it continues the process multi-hop path. Similarly, the topology can be used to shorten by bordercasting the packet. In this way, the route request routes, for example, when two nodes have moved within each spreads throughout the network. For source-routed packets, a relaying copies of the same route request, these are considered as node can determine the closest route to the destination that is redundant and are discarded [12].
The reply is sent by any node also a neighbor. Sometimes, a multi-hop segment can be that can provide a route to the destination. To be able to send replaced by a single hop. If next-hop forwarding is used, the the reply back to the source node, routing information must be nodes can make locally optimal decisions by selecting a accumulated when the request is sent through the network.
Each network configuration has an must be long enough to provide accurate measurements, but a optimal zone radius value. To determine the optimal value, long interval may not provide adequate correlation between it is necessary to understand how different factors influence consecutive intervals.
When the zone radius is less than the optimal and the ZRP traffic is more than optimal, the traffic is average node velocity v affecting route stability.
Of these, dominated by IERP queries. If the zone radius is larger than only the zone radius is a configurable parameter. Since IARP route updates are a local event, the is compared with a threshold. The zone size is increased network size does not affect the amount of proactive traffic. The amount of IERP traffic received by a node is independent A hysteresis value is used to improve stability. In this scheme of N as well. Instead, an increase in the network size increases only data collected from one measurement interval is used, the number of route queries.
Thus, the amount of reactive which improves performance in frequently changing route query traffic increases with increasing network size. Therefore, larger zone sizes are favored in large networks. It is caused by the fact that a compensates for the higher IARP maintenance costs.
To solve this problem, The amount of control traffic largely depends on the both the above schemes can be combined. The min searching relationship between node velocity and route usage. Higher scheme is then used when the radius is small one or two hops velocity causes a linear increase in IARP routing updates and and the adaptive scheme is used otherwise. IERP route failures. If the route usage rate is considerably IV. In contrast, if route usage is smaller than the one protocol.
Within the routing zone, the proactive route failure rate, the route query rate is independent of route component IARP maintains up-to-date routing tables. Routes stability and node velocity.
In this case, the load on IARP outside the routing zone are discovered with the reactive increases with the node velocity, and a small routing zone is component IERP using route requests and replies.
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Report this Document. Flag for inappropriate content. Download now. Related titles. Carousel Previous Carousel Next. Jump to Page. Search inside document. Joseph Honey. Journal of Computing. Gopakumar Sethumadhavan. Bhargava Ganti. Kuba Wilk. The number of communication neighboring nodes should be sufficient to provide adequate reachability and redundancy.
On the other hand, a too large coverage results in many zone members Network layer and the update traffic becomes excessive. The globally reactive routing component is named IntEr-zone Routing 2. Instead, IARP is a family of limited-depth, destination is within its local zone using information proactive link-state routing protocols. In that case, the packet can be routed routing information for nodes that are within the routing proactively. Reactive routing is used if the destination is zone of the node.
Correspondingly, IERP is a family of outside the zone. In the route request, the source sends a route request packet to The fact that the topology of the local zone of each node its peripheral nodes using BRP.
Otherwise, it 2. In this Route maintenance is especially important in ad-hoc way, the route request spreads throughout the network.
If networks, where links are broken and established as a node receives several copies of the same route request, nodes move relatively to each other with limited radio these are considered as redundant and are discarded [12], coverage.
In purely reactive routing protocols, routes [13] containing broken links fail and a new route discovery or route repair must be performed. Until the new route is The reply is sent by any node that can provide a route to available, packets are dropped or delayed. To be able to send the reply back to the source node, routing information must be accumulated In ZRP, the knowledge of the local topology can be used when the request is sent through the network.
The for route maintenance. Link failures and sub-optimal information is recorded either in the route request route segments within one zone can be bypassed. In the first case, the nodes forwarding a route through an active multi-hop path. The sequence is used to the closest route to the destination that is also a neighbor. In the second case, Sometimes, a multi-hop segment can be replaced by a the forwarding nodes records routing information as single hop.
If next-hop forwarding is used, the nodes can next-hop addresses, which are used when the reply is make locally optimal decisions by selecting a shorter sent to the source. This approach can save transmission path. The node S has a destination. Alternatively, the nodes along the path to the packet to send to node X. The destination record the next-hop address in their routing node uses the routing table provided by IARP to check table. Since it is not found, a route request is issued using IERP.
The request In the bordercasting process, the bordercasting node is bordercast to the peripheral nodes gray in the picture. This type of one-to-many transmission can be destination.
One approach is to let the source compute the multicast tree H and attach routing instructions to the packet. Another G C B approach is to reconstruct the tree at each node, whereas the routing instructions can be omitted. If a zone radius of one hop is used, Figure 3: The routing zone of node S routing is purely reactive and bordercasting degenerates into flood searching.
If the radius approaches infinity, Node I does not find the destination in its routing table. The selection of radius is a tradeoff Consequently, it broadcasts the request to its peripheral between the routing efficiency of proactive routing and nodes, shown in gray in Figure 4. Due to query control the increasing traffic for maintaining the view of the mechanisms, the request is not passed back to nodes D, F zone. H To solve this problem, ZRP needs query-control G C mechanisms, which can direct queries away from B covered zones and terminate query packets before they A D are delivered to peripheral nodes in regions of the S U X network already covered by the query.
J I L Query detection caches the queries relayed by the nodes. V With early termination, this information is used to prune P N bordercasting to nodes already covered by the query.
Node T appends the path from itself to node X bordercasting to their peripheral nodes, the query may be to the path in the route request. A route reply, containing relayed through the same nodes again. To illustrate with the reversed path is generated and sent back to the source an example, the node S in Figure 6 bordercasts a query node.
If multiple paths to the destination were available, to its peripheral nodes F—J. As the node J continues by the source would receive several replies. The query issued by node J to H nodes C, S and E is redundant, since these nodes have been covered by the previous query. BRP provides two query detection nodes, and thus only on the corresponding links. Further methods: QD1 and QD2. Firstly, the nodes that relay the efficiency can be gained by utilizing multicast query are able to detect the query QD1.
Secondly, in techniques. In that case, only one packet is sent on a link single-channel networks, it is possible to listen to the although several peripheral nodes can reside behind this traffic by other nodes within the radio coverage QD2. QD2 can be implemented by using IP However, since the routing zones of neighboring nodes broadcasts to send route queries. Alternative, unicast can overlap, each node may forward route requests several be used if the MAC and IP layers operate in promiscuous times, which results in more traffic than in flooding.
Any further query messages In the above example, all nodes except node B relay the entering the zone are redundant and result in wasted query of S. They are thus able to use QD1. Node B does transmission capacity. The excess traffic is a result from not belong to the bordercast tree, but it is able to queries returning to covered zones instead of covered overhear the relayed query using QD2. However, node K nodes as in traditional flooding. When a node issues a node request, it takes some time for the query to be relayed along the bordercast tree and A query detection table is used to cache the detected to be detected through the query detection mechanisms.
For each entry, the cache contains the address of During this time, another node may propagate the same the source node and the query ID. The address—ID pair is request. This can be a problem when several nearby sufficient to uniquely identify all queries in the network. Especially the address of the node that most recently bordercasted a query is To reduce the probability of receiving the same request important. Each bordercasting node 3.
During this request from entering already covered regions. Early time, the waiting node can detect queries from other termination combines information obtained through bordercasting nodes and prune the bordercast tree. To query detection with the knowledge of the local topology avoid additional route discovery delay, the delay can be to prune branches leading to peripheral nodes inside combined with the pre-transmission jitter used by many covered regions.
These regions consist of the interior route discovery protocols. A node can also prune a peripheral node if it has already Assume that in Figure 7 the nodes C and S both receive a relayed a query to that node. Node C schedules a bordercast to its peripheral node E, and node S to its peripheral node F. Without Early termination requires topology information RQPD, both nodes would issue the broadcast extending outside the routing zone of the node.
The simultaneously, and thereafter detect the message of the information is required to reconstruct the bordercast tree neighbor node. Alternatively, in the branch leading to E. The nodes cache active In the previous example, node E can use the information routes, and by using this cache, the frequency of route in its query detection table to prune the query that the discovery procedures can be reduced.
Changes in node J sends to its peripheral node F. A new path then dashed circle in Figure 7. Since the repair reduces the efficiency of the I routes, the endpoints may initiate a new route discovery K procedure after a number of repairs. These are described in terms of packet format, data structures, state G machine and pseudo code implementation.
When a node receives a route request for a away are discarded. In this way, redundant link state the request with BRP. On the other hand, if the node has transmissions are reduced to neighbors closer to the link a route to the requested destination, it appends the route source, and transmission of out-of-zone link state to to the route in the request, and creates a reply packet neighbors farther away is prevented.
The route reply is forwarded back to the query source along the reversed accumulated route. Correspondingly, a reactive routing protocol can be converted into an IERP. For each IERP route affected by the There should not be any local proactive route updates change, an alternative path through the routing zone is and neighbor advertisements, since this functionality is identified.
The new path minimizes the distance to the performed by IARP. Instead of broadcasting route destination, and can thus bypass failed links and sub- request packets, the protocol should bordercast the route optimal segments. Flood control and other forms of redundant query termination must be disabled since this The packet format is similar for route requests and route is handled by BRP. Nevertheless, route requests can be replies, with an identifier indicating the type.
The packet discarded based on other criteria, such as successful contains a list of IP addresses built along the path: the route discovery, exceeded QoS metrics and expired TTL.
The destination. A pointer identifies the next node in the list protocol may use advanced route maintenance to forward the packet to. A query ID is used to uniquely techniques, such as on-line route repair and route identify the request for limiting the propagation.
IERP shortening. The IARP should support link state metrics that are 4. This is required for The draft [13] describes the operation of BRP.
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