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Primary path reservation using enhanced slot assignment in TDMA for session admission.

Koneri Chandrasekaran S, Savarimuthu P, Andi Elumalai P, Ayyaswamy K - ScientificWorldJournal (2015)

Bottom Line: In such cases the QoS session is affected.Many TDMA based reservation mechanisms are proposed but need some improvement over slot reservation procedures.A network topology has been simulated and our approach proves to be a mechanism that admits the session effectively.

View Article: PubMed Central - PubMed

Affiliation: Department of Computer Science and Engineering, Tagore Engineering College, Chennai 600127, India.

ABSTRACT
Mobile ad hoc networks (MANET) is a self-organized collection of nodes that communicates without any infrastructure. Providing quality of service (QoS) in such networks is a competitive task due to unreliable wireless link, mobility, lack of centralized coordination, and channel contention. The success of many real time applications is purely based on the QoS, which can be achieved by quality aware routing (QAR) and admission control (AC). Recently proposed QoS mechanisms do focus completely on either reservation or admission control but are not better enough. In MANET, high mobility causes frequent path break due to the fact that every time the source node must find the route. In such cases the QoS session is affected. To admit a QoS session, admission control protocols must ensure the bandwidth of the relaying path before transmission starts; reservation of such bandwidth noticeably improves the admission control performance. Many TDMA based reservation mechanisms are proposed but need some improvement over slot reservation procedures. In order to overcome this specific issue, we propose a framework-PRAC (primary path reservation admission control protocol), which achieves improved QoS by making use of backup route combined with resource reservation. A network topology has been simulated and our approach proves to be a mechanism that admits the session effectively.

No MeSH data available.


Related in: MedlinePlus

Capacity constraint route discovering process.
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Related In: Results  -  Collection


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fig1: Capacity constraint route discovering process.

Mentions: Studies on backup route discovery emphasize that many backup routes have to be maintained to overcome re-routing process after a route failure. The disadvantage of the above stated method is that since many control packets are sent through and forth, there is a consistent increase in the network overhead. In PRAC, we maintain a primary path and a single backup path. From previous analysis, dynamic source routing (DSR) [21] proves to be a suitable routing protocol for finding backup routes. The backup route discovery process finds the route in which the nodes involved in the process are in a complete disjoint set. The backup path discovered should not include the nodes that were in the primary path [12]. Results from [13] which include many backup routes prove that the nodes in primary and backup routes can be sufficiently disjoint and are not required to be in full disjoint sets. Consider(1)Rprimary∩Rbackup≤Rprimary2,where Rprimary is the primary path and Rbackup is the backup path. But in PRAC since only one backup route is maintained, the backup route nodes should be a complete disjoint set with that of the primary route nodes:(2)Rprimary∩Rbackup  =  0.If many backup paths are maintained, the condition for partial or sufficient disjoint sets may yield better performance, whereas, in the case of a single backup, if the primary path fails then the probability of backup failure is also feasible. Hence the backup path nodes should be a complete disjoint set, thereby reducing the risk of failure. The capacity constraint route discovering process is explained in Figure 1. The route discovery process starts with the request for session. In this, the source node broadcasts the RREQ packet to all its neighbouring nodes. Each node calculates its own residual capacity, which if satisfies the capacity requested by a session, will rebroadcast the RREQ packet to their neighbours. The session capacity requirement BWreq can be calculated as follows:(3)BWreq=b∗ncs.This equation is used to calculate the session capacity requirement at any node. Here b is the number of slots required and ncs is the number of contenting nodes in the carrier sensing range. MACMAN [12] implements high power method that builds up ncs sets, which in turn increases the beacon overhead making it a probable disadvantage. Our proposed PRAC method overcomes it by the use of admission request packet (similar to CACP-Multihop), flooded through the network, covering a two-hop radius at the time of session admission, depending upon the session capacity; a node may confirm the session admission or deny it. In the case of primary route failure, backup route discovery is initiated, in which the process is decoupled from the normal route discovery mechanism and only admission control mechanism takes place.


Primary path reservation using enhanced slot assignment in TDMA for session admission.

Koneri Chandrasekaran S, Savarimuthu P, Andi Elumalai P, Ayyaswamy K - ScientificWorldJournal (2015)

Capacity constraint route discovering process.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4385671&req=5

fig1: Capacity constraint route discovering process.
Mentions: Studies on backup route discovery emphasize that many backup routes have to be maintained to overcome re-routing process after a route failure. The disadvantage of the above stated method is that since many control packets are sent through and forth, there is a consistent increase in the network overhead. In PRAC, we maintain a primary path and a single backup path. From previous analysis, dynamic source routing (DSR) [21] proves to be a suitable routing protocol for finding backup routes. The backup route discovery process finds the route in which the nodes involved in the process are in a complete disjoint set. The backup path discovered should not include the nodes that were in the primary path [12]. Results from [13] which include many backup routes prove that the nodes in primary and backup routes can be sufficiently disjoint and are not required to be in full disjoint sets. Consider(1)Rprimary∩Rbackup≤Rprimary2,where Rprimary is the primary path and Rbackup is the backup path. But in PRAC since only one backup route is maintained, the backup route nodes should be a complete disjoint set with that of the primary route nodes:(2)Rprimary∩Rbackup  =  0.If many backup paths are maintained, the condition for partial or sufficient disjoint sets may yield better performance, whereas, in the case of a single backup, if the primary path fails then the probability of backup failure is also feasible. Hence the backup path nodes should be a complete disjoint set, thereby reducing the risk of failure. The capacity constraint route discovering process is explained in Figure 1. The route discovery process starts with the request for session. In this, the source node broadcasts the RREQ packet to all its neighbouring nodes. Each node calculates its own residual capacity, which if satisfies the capacity requested by a session, will rebroadcast the RREQ packet to their neighbours. The session capacity requirement BWreq can be calculated as follows:(3)BWreq=b∗ncs.This equation is used to calculate the session capacity requirement at any node. Here b is the number of slots required and ncs is the number of contenting nodes in the carrier sensing range. MACMAN [12] implements high power method that builds up ncs sets, which in turn increases the beacon overhead making it a probable disadvantage. Our proposed PRAC method overcomes it by the use of admission request packet (similar to CACP-Multihop), flooded through the network, covering a two-hop radius at the time of session admission, depending upon the session capacity; a node may confirm the session admission or deny it. In the case of primary route failure, backup route discovery is initiated, in which the process is decoupled from the normal route discovery mechanism and only admission control mechanism takes place.

Bottom Line: In such cases the QoS session is affected.Many TDMA based reservation mechanisms are proposed but need some improvement over slot reservation procedures.A network topology has been simulated and our approach proves to be a mechanism that admits the session effectively.

View Article: PubMed Central - PubMed

Affiliation: Department of Computer Science and Engineering, Tagore Engineering College, Chennai 600127, India.

ABSTRACT
Mobile ad hoc networks (MANET) is a self-organized collection of nodes that communicates without any infrastructure. Providing quality of service (QoS) in such networks is a competitive task due to unreliable wireless link, mobility, lack of centralized coordination, and channel contention. The success of many real time applications is purely based on the QoS, which can be achieved by quality aware routing (QAR) and admission control (AC). Recently proposed QoS mechanisms do focus completely on either reservation or admission control but are not better enough. In MANET, high mobility causes frequent path break due to the fact that every time the source node must find the route. In such cases the QoS session is affected. To admit a QoS session, admission control protocols must ensure the bandwidth of the relaying path before transmission starts; reservation of such bandwidth noticeably improves the admission control performance. Many TDMA based reservation mechanisms are proposed but need some improvement over slot reservation procedures. In order to overcome this specific issue, we propose a framework-PRAC (primary path reservation admission control protocol), which achieves improved QoS by making use of backup route combined with resource reservation. A network topology has been simulated and our approach proves to be a mechanism that admits the session effectively.

No MeSH data available.


Related in: MedlinePlus