The document proposes a hybrid network-on-chip (NoC) architecture that combines spatial division multiplexing (SDM)-based circuit switching and packet switching. The SDM-based circuit-switched sub-network handles streaming traffic, using SDM to increase path diversity and improve throughput. The packet-switched sub-network handles best-effort traffic and configures the circuit-switched sub-network. The hybrid router architecture was implemented in FPGA and ASIC, showing it can build a practical hybrid NoC while providing quality of service for streaming traffic without complex resource sharing.
Optimized Link State Routing (OLSR) protocol is a proactive type of routing protocol that uses Multipoint
Relay (MPR) set as the virtual backbone structure. The existing literature has identified various issues with
respect to its backbone structure and has accordingly proposed improvements. In this paper, the focus is on
improving the OLSR protocol by employing a Connected Dominating Set (CDS) based virtual backbone
structure that is dynamically adaptable to rapid topology changes. A new Dynamically Adaptable Improved
Optimized Link State Routing (DA-IOLSR) protocol is proposed that uses the local topology information to
adapt the virtual backbone to topology changes. This assumes significance especially in networks that
experience very high mobility. Changes in the network topology caused by node additions, node deletions
and node mobility are taken care of. Simulations are carried out to assess the performance of DA-IOLSR
protocol and OLSR protocol. Packet delivery achieved by both the protocols is examined under varying
mobility by using various combinations of node speed and pause time values. It is found that DA-IOLSR
protocol provides better packet delivery as compared to OLSR protocol, under varying mobility conditions.
WARM WELCOME FROM HCL VELACHERY…….
HCL Learning is part of HCL Info Systems Ltd, India’s Premier information enabling company with an annual turnover of 15000 crores Leveraging on the 34 years of industry experience of HCL, with an objective to develop quality IT professionals to meet this ever expanding requirement of Hardware Networking and Software professionals for the IT sector, HCL has launched HCL Career Development Centre.
For any clarification,
contact Person
Mr.Senthilvel.S
9382207007
HCL Velachery -42
Recently proposed wireless mesh routing metrics
based on awareness of congestion, load or interference typically
employ queue occupancy of a node's wireless interface to
estimate traffic load. Queue occupancy, however, does not
directly reflect the impact of channel contention from neighbor
nodes. We propose an alternative called the channel load-aware
(CLAW) routing metric that takes into consideration not only
the traffic load within the node itself, but also the degree of
interference and contention within the channel. CLAW uses
local information from a node's MAC layer to estimate channel
busyness and contention levels. It does not require complex
computations, nor the exchange of link-level statistics with
neighbors. Our preliminary results show that CLAW can
identify congested regions within the network and thus enable
the determination of routes around these congested areas. We
present the results of simulations we conducted to evaluate the
use of CLAW in mesh-wide routing.
BETTER SCALABLE ROUTING PROTOCOL FOR HYBRID WIRELESS MESH NETWORKcscpconf
There are many routing approaches have been borrowed from mobile ad hoc network to achieve routing solutions in wireless mesh network. WMN was developed for reliable data communication and load balancing. AODV provides loop-free routes even while repairing broken links. This paper have been proposed an improved hierarchical AODV routing protocol
(IH-AODV), which exhibits better scalability and performance in the network. This IH-AODV protocol has been proposed for improvement in the scaling potential of AODV. MAODV allows
each node in the network to send out multicast data packets, used for multicast traffic. The wireless mesh network architecture provides reduction in installation cost, large scale
deployment, reliability and self management. It is mainly focused on implementing military or specialized civilian applications. Two protocols MAODV and IH-AODV were simulated using NS2 package. Simulation results will demonstrate that, IH-AODV scales well for large network
and other metrics are also better than or comparable to MAODV in hybrid WMNs.
Optimized Link State Routing (OLSR) protocol is a proactive type of routing protocol that uses Multipoint
Relay (MPR) set as the virtual backbone structure. The existing literature has identified various issues with
respect to its backbone structure and has accordingly proposed improvements. In this paper, the focus is on
improving the OLSR protocol by employing a Connected Dominating Set (CDS) based virtual backbone
structure that is dynamically adaptable to rapid topology changes. A new Dynamically Adaptable Improved
Optimized Link State Routing (DA-IOLSR) protocol is proposed that uses the local topology information to
adapt the virtual backbone to topology changes. This assumes significance especially in networks that
experience very high mobility. Changes in the network topology caused by node additions, node deletions
and node mobility are taken care of. Simulations are carried out to assess the performance of DA-IOLSR
protocol and OLSR protocol. Packet delivery achieved by both the protocols is examined under varying
mobility by using various combinations of node speed and pause time values. It is found that DA-IOLSR
protocol provides better packet delivery as compared to OLSR protocol, under varying mobility conditions.
WARM WELCOME FROM HCL VELACHERY…….
HCL Learning is part of HCL Info Systems Ltd, India’s Premier information enabling company with an annual turnover of 15000 crores Leveraging on the 34 years of industry experience of HCL, with an objective to develop quality IT professionals to meet this ever expanding requirement of Hardware Networking and Software professionals for the IT sector, HCL has launched HCL Career Development Centre.
For any clarification,
contact Person
Mr.Senthilvel.S
9382207007
HCL Velachery -42
Recently proposed wireless mesh routing metrics
based on awareness of congestion, load or interference typically
employ queue occupancy of a node's wireless interface to
estimate traffic load. Queue occupancy, however, does not
directly reflect the impact of channel contention from neighbor
nodes. We propose an alternative called the channel load-aware
(CLAW) routing metric that takes into consideration not only
the traffic load within the node itself, but also the degree of
interference and contention within the channel. CLAW uses
local information from a node's MAC layer to estimate channel
busyness and contention levels. It does not require complex
computations, nor the exchange of link-level statistics with
neighbors. Our preliminary results show that CLAW can
identify congested regions within the network and thus enable
the determination of routes around these congested areas. We
present the results of simulations we conducted to evaluate the
use of CLAW in mesh-wide routing.
BETTER SCALABLE ROUTING PROTOCOL FOR HYBRID WIRELESS MESH NETWORKcscpconf
There are many routing approaches have been borrowed from mobile ad hoc network to achieve routing solutions in wireless mesh network. WMN was developed for reliable data communication and load balancing. AODV provides loop-free routes even while repairing broken links. This paper have been proposed an improved hierarchical AODV routing protocol
(IH-AODV), which exhibits better scalability and performance in the network. This IH-AODV protocol has been proposed for improvement in the scaling potential of AODV. MAODV allows
each node in the network to send out multicast data packets, used for multicast traffic. The wireless mesh network architecture provides reduction in installation cost, large scale
deployment, reliability and self management. It is mainly focused on implementing military or specialized civilian applications. Two protocols MAODV and IH-AODV were simulated using NS2 package. Simulation results will demonstrate that, IH-AODV scales well for large network
and other metrics are also better than or comparable to MAODV in hybrid WMNs.
EFFICIENT MULTI-PATH PROTOCOL FOR WIRELESS SENSOR NETWORKSijwmn
Wireless sensor networks are useful for streaming multimedia in infrastructure-free and hazardous environments. However, these networks are quite different from their wired counterpart and are composed of nodes with constrained bandwidth and energy. Multiple-path transmission is one of the methods for ensuring QoS routing in both wired and wireless environment. Directed diffusion, a well known wireless sensor network protocol, only routes packets through a single path, which barely meets the throughput requirement of multimedia data. Instead, we propose a multipath algorithm based on directed diffusion that reinforces multiple routes with high link quality and low latency. This algorithm retains the merits of the original directed diffusion algorithms, including its energy efficiency and scalability. A hybrid metric of link quality and latency is used as the criterion for path selection. In order to select disjoint paths, we propose a scheme for reinforced nodes to respond negatively to multiple reinforcement messages. We use the NS-2 simulation tool with video trace generated by Multiple Description Coding (MDC) to evaluate the performance. The results show that our algorithm gives better throughput and delay performance, i.e higher video quality, than standard directed diffusion that transmits over a single path, with low overheads and energy consumption.
A Low Control Overhead Cluster Maintenance Scheme for Mobile Ad hoc NETworks ...Narendra Singh Yadav
Clustering is an important research area for mobile ad hoc networks (MANETs) as it increases the capacity of network, reduces the routing overhead and makes the network more scalable in the presence of both high mobility and a large number of mobile nodes. In clustering the clusterhead manage and store recent routing information. However the frequent change of clusterhead leads to loss of routing information stored, changes the route between two nodes, affects the performance of the routing protocol and makes the cluster structure unstable. Communication overhead in terms of exchanging messages is needed to elect a new clusterhead. The goal then would be to keep the clusterhead change as least as possible to make cluster structure more stable, to prevent loss of routing information which in turn improve the performance of routing protocol based on clustering. This can be achieved by an efficient cluster maintenance scheme. In this work, a novel clustering algorithm, namely Incremental Maintenance Clustering Scheme (IMS) is proposed for Mobile Ad Hoc Networks. The goals are yielding low number of clusterhead and clustermember changes, maintaining stable clusters, minimizing the number of clustering overhead. Through simulations the performance of IMS is compared with that of least cluster change (LCC) and maintenance scheme of Cluster Based Routing Protocol (CBRP) in terms of the number of clusterhead changes, number of cluster-member changes and clustering overhead by varying mobility and speed. The simulation results demonstrate the superiority of IMS over LCC and
maintenance scheme of CBRP.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
A Low Control Overhead Cluster Maintenance Scheme for Mobile Ad hoc NETworks ...IDES Editor
Clustering is an important research area for
mobile ad hoc networks (MANETs) as it increases the
capacity of network, reduces the routing overhead and
makes the network more scalable in the presence of both
high mobility and a large number of mobile nodes. In
clustering the clusterhead manage and store recent routing
information. However the frequent change of clusterhead
leads to loss of routing information stored, changes the route
between two nodes, affects the performance of the routing
protocol and makes the cluster structure unstable.
Communication overhead in terms of exchanging messages
is needed to elect a new clusterhead. The goal then would be
to keep the clusterhead change as least as possible to make
cluster structure more stable, to prevent loss of routing
information which in turn improve the performance of
routing protocol based on clustering. This can be achieved
by an efficient cluster maintenance scheme. In this work, a
novel clustering algorithm, namely Incremental
Maintenance Clustering Scheme (IMS) is proposed for
Mobile Ad Hoc Networks. The goals are yielding low
number of clusterhead and clustermember changes,
maintaining stable clusters, minimizing the number of
clustering overhead. Through simulations the performance
of IMS is compared with that of least cluster change (LCC)
and maintenance scheme of Cluster Based Routing Protocol
(CBRP) in terms of the number of clusterhead changes,
number of cluster-member changes and clustering overhead
by varying mobility and speed. The simulation results
demonstrate the superiority of IMS over LCC and
maintenance scheme of CBRP.
Haqr the hierarchical ant based qos aware on demand routing for manetscsandit
A Mobile Ad Hoc Network (MANET) is a collection of wireless mobile devices with no pre
existing infrastructure or centralized control. Supporting QoS during routing is a very
challenging task. Clustering is an effective method for resource management regarding network
performance, routing protocol design, QoS etc. In real time various types of nodes with different
computing and transmission power, different rolls and different mobility pattern may exist.
Hierarchical routing provides routing through this kind of heterogeneous nodes. In this paper,
HAQR, a novel ant based QoS aware routing is proposed on a three level hierarchical cluster
based topology in MANET which will be more scalable and efficient compared to flat
architecture and will give better throughput.
IOSR Journal of Electronics and Communication Engineering(IOSR-JECE) is an open access international journal that provides rapid publication (within a month) of articles in all areas of electronics and communication engineering and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in electronics and communication engineering. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Improved Good put using Harvest-Then-Transmit Protocol for Video TransferEswar Publications
In multiple wireless networks, large end-to-end delay and packet losses can decrease meaningfully the traffic flow goodput due to path irregularity and multiplicity. To report these problems, current methods are proposed by using management of queue and decision making process. Hence, this paper proposesa Harvest-Then-Transmit (HTT) Protocol which selects an energy efficient path based on multiple parameters i.e. energy, delay, transmission time and perform transmission of video to handle number of video packets. A multipath environment is establishing where a server performs transferring of video along the energy efficient path of wireless network. Simulation shows the proposed protocol improves the overall goodput up to 10%, increases packet delivery rate up to 12%, and reduces end-to-end delay up to 3%, compared to existing system.
Performance Comparison of AODV and DSDV Routing Protocols for Ad-hoc Wireless...Narendra Singh Yadav
An ad hoc network is a collection of mobile nodes communicating through wireless channels without any existing network infrastructure or centralized administration. Because of the limited transmission range of wireless network interfaces, multiple “hops” may be needed to exchange data across the network. Consequently, many routing algorithms have come into existence to satisfy the needs of communications in such networks. This paper presents performance comparison of the three routing protocols AODV and DSDV. Protocols were simulated using the ns-2 and were compared in terms of packet delivery fraction, normalized routing load and average delay, while varying number of nodes, and pause time. Simulation revealed that although DSDV perfectly scales to small networks with low node speeds, AODV is preferred due to its more efficient use of bandwidth.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
With the increase of usage of wireless networks for purposes where the nodes are either stationary or minimally mobile, focus is also on increasing the network capacity of wireless networks. One such way is to use non-overlapping multiple channels provided by 802.11 by using multiple interfaces per node. Multiple non overlapped channels exist in the 2.4 GHz and 5 GHz spectrum. Under this scenario, several challenges need to be addressed before all the available channels can be fully utilized.
ENERGY EFFICIENT MULTICAST ROUTING IN MANET ijac journal
In this paper, we have presented the Modified Multicasting through Time Reservation using Adaptive
Control for Excellent Energy efficiency (MMC-TRACE). It is a real time multicasting architecture for
Mobile Ad-Hoc networks to make their work an energy efficient one .MMC-TRACE is a cross layer design
where the network layer and medium access control layer functionality are done in a single integrated
layer design. The basic design of the architecture is to establish and maintain an active multicast tree
surrounded by a passive mesh within a mobile ad hoc network. Energy efficiency is maximized by enabling
the particular node from sleep to awake mode while the remaining nodes of the same path are maintained
at sleep mode. Energy efficiency too achieved by eliminating most of the redundant data receptions across
nodes. The performance of MMC-TRACE are evaluated with the help of ns-2 simulations and comparisons
are made with its predecessor such as MC-TRACE. The results show that the MMC-TRACE provides
superior energy efficiency, competitive QoS performance and bandwidth efficiency.
EFFICIENT MULTI-PATH PROTOCOL FOR WIRELESS SENSOR NETWORKSijwmn
Wireless sensor networks are useful for streaming multimedia in infrastructure-free and hazardous environments. However, these networks are quite different from their wired counterpart and are composed of nodes with constrained bandwidth and energy. Multiple-path transmission is one of the methods for ensuring QoS routing in both wired and wireless environment. Directed diffusion, a well known wireless sensor network protocol, only routes packets through a single path, which barely meets the throughput requirement of multimedia data. Instead, we propose a multipath algorithm based on directed diffusion that reinforces multiple routes with high link quality and low latency. This algorithm retains the merits of the original directed diffusion algorithms, including its energy efficiency and scalability. A hybrid metric of link quality and latency is used as the criterion for path selection. In order to select disjoint paths, we propose a scheme for reinforced nodes to respond negatively to multiple reinforcement messages. We use the NS-2 simulation tool with video trace generated by Multiple Description Coding (MDC) to evaluate the performance. The results show that our algorithm gives better throughput and delay performance, i.e higher video quality, than standard directed diffusion that transmits over a single path, with low overheads and energy consumption.
A Low Control Overhead Cluster Maintenance Scheme for Mobile Ad hoc NETworks ...Narendra Singh Yadav
Clustering is an important research area for mobile ad hoc networks (MANETs) as it increases the capacity of network, reduces the routing overhead and makes the network more scalable in the presence of both high mobility and a large number of mobile nodes. In clustering the clusterhead manage and store recent routing information. However the frequent change of clusterhead leads to loss of routing information stored, changes the route between two nodes, affects the performance of the routing protocol and makes the cluster structure unstable. Communication overhead in terms of exchanging messages is needed to elect a new clusterhead. The goal then would be to keep the clusterhead change as least as possible to make cluster structure more stable, to prevent loss of routing information which in turn improve the performance of routing protocol based on clustering. This can be achieved by an efficient cluster maintenance scheme. In this work, a novel clustering algorithm, namely Incremental Maintenance Clustering Scheme (IMS) is proposed for Mobile Ad Hoc Networks. The goals are yielding low number of clusterhead and clustermember changes, maintaining stable clusters, minimizing the number of clustering overhead. Through simulations the performance of IMS is compared with that of least cluster change (LCC) and maintenance scheme of Cluster Based Routing Protocol (CBRP) in terms of the number of clusterhead changes, number of cluster-member changes and clustering overhead by varying mobility and speed. The simulation results demonstrate the superiority of IMS over LCC and
maintenance scheme of CBRP.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
A Low Control Overhead Cluster Maintenance Scheme for Mobile Ad hoc NETworks ...IDES Editor
Clustering is an important research area for
mobile ad hoc networks (MANETs) as it increases the
capacity of network, reduces the routing overhead and
makes the network more scalable in the presence of both
high mobility and a large number of mobile nodes. In
clustering the clusterhead manage and store recent routing
information. However the frequent change of clusterhead
leads to loss of routing information stored, changes the route
between two nodes, affects the performance of the routing
protocol and makes the cluster structure unstable.
Communication overhead in terms of exchanging messages
is needed to elect a new clusterhead. The goal then would be
to keep the clusterhead change as least as possible to make
cluster structure more stable, to prevent loss of routing
information which in turn improve the performance of
routing protocol based on clustering. This can be achieved
by an efficient cluster maintenance scheme. In this work, a
novel clustering algorithm, namely Incremental
Maintenance Clustering Scheme (IMS) is proposed for
Mobile Ad Hoc Networks. The goals are yielding low
number of clusterhead and clustermember changes,
maintaining stable clusters, minimizing the number of
clustering overhead. Through simulations the performance
of IMS is compared with that of least cluster change (LCC)
and maintenance scheme of Cluster Based Routing Protocol
(CBRP) in terms of the number of clusterhead changes,
number of cluster-member changes and clustering overhead
by varying mobility and speed. The simulation results
demonstrate the superiority of IMS over LCC and
maintenance scheme of CBRP.
Haqr the hierarchical ant based qos aware on demand routing for manetscsandit
A Mobile Ad Hoc Network (MANET) is a collection of wireless mobile devices with no pre
existing infrastructure or centralized control. Supporting QoS during routing is a very
challenging task. Clustering is an effective method for resource management regarding network
performance, routing protocol design, QoS etc. In real time various types of nodes with different
computing and transmission power, different rolls and different mobility pattern may exist.
Hierarchical routing provides routing through this kind of heterogeneous nodes. In this paper,
HAQR, a novel ant based QoS aware routing is proposed on a three level hierarchical cluster
based topology in MANET which will be more scalable and efficient compared to flat
architecture and will give better throughput.
IOSR Journal of Electronics and Communication Engineering(IOSR-JECE) is an open access international journal that provides rapid publication (within a month) of articles in all areas of electronics and communication engineering and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in electronics and communication engineering. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Improved Good put using Harvest-Then-Transmit Protocol for Video TransferEswar Publications
In multiple wireless networks, large end-to-end delay and packet losses can decrease meaningfully the traffic flow goodput due to path irregularity and multiplicity. To report these problems, current methods are proposed by using management of queue and decision making process. Hence, this paper proposesa Harvest-Then-Transmit (HTT) Protocol which selects an energy efficient path based on multiple parameters i.e. energy, delay, transmission time and perform transmission of video to handle number of video packets. A multipath environment is establishing where a server performs transferring of video along the energy efficient path of wireless network. Simulation shows the proposed protocol improves the overall goodput up to 10%, increases packet delivery rate up to 12%, and reduces end-to-end delay up to 3%, compared to existing system.
Performance Comparison of AODV and DSDV Routing Protocols for Ad-hoc Wireless...Narendra Singh Yadav
An ad hoc network is a collection of mobile nodes communicating through wireless channels without any existing network infrastructure or centralized administration. Because of the limited transmission range of wireless network interfaces, multiple “hops” may be needed to exchange data across the network. Consequently, many routing algorithms have come into existence to satisfy the needs of communications in such networks. This paper presents performance comparison of the three routing protocols AODV and DSDV. Protocols were simulated using the ns-2 and were compared in terms of packet delivery fraction, normalized routing load and average delay, while varying number of nodes, and pause time. Simulation revealed that although DSDV perfectly scales to small networks with low node speeds, AODV is preferred due to its more efficient use of bandwidth.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
With the increase of usage of wireless networks for purposes where the nodes are either stationary or minimally mobile, focus is also on increasing the network capacity of wireless networks. One such way is to use non-overlapping multiple channels provided by 802.11 by using multiple interfaces per node. Multiple non overlapped channels exist in the 2.4 GHz and 5 GHz spectrum. Under this scenario, several challenges need to be addressed before all the available channels can be fully utilized.
ENERGY EFFICIENT MULTICAST ROUTING IN MANET ijac journal
In this paper, we have presented the Modified Multicasting through Time Reservation using Adaptive
Control for Excellent Energy efficiency (MMC-TRACE). It is a real time multicasting architecture for
Mobile Ad-Hoc networks to make their work an energy efficient one .MMC-TRACE is a cross layer design
where the network layer and medium access control layer functionality are done in a single integrated
layer design. The basic design of the architecture is to establish and maintain an active multicast tree
surrounded by a passive mesh within a mobile ad hoc network. Energy efficiency is maximized by enabling
the particular node from sleep to awake mode while the remaining nodes of the same path are maintained
at sleep mode. Energy efficiency too achieved by eliminating most of the redundant data receptions across
nodes. The performance of MMC-TRACE are evaluated with the help of ns-2 simulations and comparisons
are made with its predecessor such as MC-TRACE. The results show that the MMC-TRACE provides
superior energy efficiency, competitive QoS performance and bandwidth efficiency.
Influence of Clustering on the Performance of MobileAd Hoc Networks (MANETs)Narendra Singh Yadav
Clustering is an important research area for mobile ad hoc networks (MANETs) as it increases the capacity of network, reduces the routing overhead and makes the network more scalable in the presence of both high mobility and a large number of mobile nodes. Routing protocols based on flat topology are not scalable because of their built-in characteristics. However, clustering cause overhead which consumes considerable bandwidth, drain mobile nodes energy quickly, likely cause congestion, collision and data delay in larger networks. This paper uses an implementation of the Dynamic Source Routing (DSR), an flat architecture based and the Cluster Based Routing Protocol (CBRP), a cluster architecture based routing protocol to examine the influence of clustering on the performance of mobile ad hoc networks. This paper evaluates channel utilization and control overhead as a function of number of nodes per sq. km to show the effect of clustering. Simulation results show that in high mobility scenarios, CBRP outperforms DSR. CBRP scales well with increasing number of nodes.
A scalable and power efficient solution for routing in mobile ad hoc network ...ijmnct
Mobile Ad Hoc Network (MANET) is a very dynamic and infrastructure-less ad hoc network. The actual
network size depends on the application and the protocols developed for the routing for this kind of
networks should be scalable. MANET is a resource limited network and therefore the developed routing
algorithm for packet transmission should be power and bandwidth efficient. These kinds of dynamic
networks should operate with minimal management overhead. The management functionality of the
network increases with number of nodes and reduces the performance of the network. Here, in this paper,
we have designed all identical nodes in the cluster except the cluster head and this criterion reduces the
management burden on the network. Graph theoretic routing algorithm is used to develop route for packet
transmission by using the minimum resources. In this paper, we developed routing algorithm for cluster
based MANET and finds a path from source to destination using minimum cumulative degree path. Our
simulation results show that this routing algorithm provide efficient routing path with the increasing
number of nodes and uses multi-hop connectivity for intra-cluster to utilize minimum power for packet
transmission irrespective of number of nodes in the network.
DETERMINING THE NETWORK THROUGHPUT AND FLOW RATE USING GSR AND AAL2Rijujournal
In multi-radio wireless mesh networks, one node is eligible to transmit packets over multiple channels to
different destination nodes simultaneously. This feature of multi-radio wireless mesh network makes high
throughput for the network and increase the chance for multi path routing. This is because the multiple
channel availability for transmission decreases the probability of the most elegant problem called as
interference problem which is either of interflow and intraflow type. For avoiding the problem like
interference and maintaining the constant network performance or increasing the performance the WMN
need to consider the packet aggregation and packet forwarding. Packet aggregation is process of collecting
several packets ready for transmission and sending them to the intended recipient through the channel,
while the packet forwarding holds the hop-by-hop routing. But choosing the correct path among different
available multiple paths is most the important factor in the both case for a routing algorithm. Hence the
most challenging factor is to determine a forwarding strategy which will provide the schedule for each
node for transmission within the channel. In this research work we have tried to implement two forwarding
strategies for the multi path multi radio WMN as the approximate solution for the above said problem. We
have implemented Global State Routing (GSR) which will consider the packet forwarding concept and
Aggregation Aware Layer 2 Routing (AAL2R) which considers the both concept i.e. both packet forwarding
and packet aggregation. After the successful implementation the network performance has been measured
by means of simulation study.
DETERMINING THE NETWORK THROUGHPUT AND FLOW RATE USING GSR AND AAL2Rijujournal
In multi-radio wireless mesh networks, one node is eligible to transmit packets over multiple channels to
different destination nodes simultaneously. This feature of multi-radio wireless mesh network makes high
throughput for the network and increase the chance for multi path routing. This is because the multiple
channel availability for transmission decreases the probability of the most elegant problem called as
interference problem which is either of interflow and intraflow type. For avoiding the problem like
interference and maintaining the constant network performance or increasing the performance the WMN
need to consider the packet aggregation and packet forwarding. Packet aggregation is process of collecting
several packets ready for transmission and sending them to the intended recipient through the channel,
while the packet forwarding holds the hop-by-hop routing. But choosing the correct path among different
available multiple paths is most the important factor in the both case for a routing algorithm. Hence the
most challenging factor is to determine a forwarding strategy which will provide the schedule for each
node for transmission within the channel. In this research work we have tried to implement two forwarding
strategies for the multi path multi radio WMN as the approximate solution for the above said problem. We
have implemented Global State Routing (GSR) which will consider the packet forwarding concept and
Aggregation Aware Layer 2 Routing (AAL2R) which considers the both concept i.e. both packet forwarding
and packet aggregation. After the successful implementation the network performance has been measured
by means of simulation study.
DETERMINING THE NETWORK THROUGHPUT AND FLOW RATE USING GSR AND AAL2Rijujournal
In multi-radio wireless mesh networks, one node is eligible to transmit packets over multiple channels to different destination nodes simultaneously. This feature of multi-radio wireless mesh network makes high throughput for the network and increase the chance for multi path routing. This is because the multiple channel availability for transmission decreases the probability of the most elegant problem called as interference problem which is either of interflow and intraflow type. For avoiding the problem like interference and maintaining the constant network performance or increasing the performance the WMN need to consider the packet aggregation and packet forwarding. Packet aggregation is process of collecting several packets ready for transmission and sending them to the intended recipient through the channel, while the packet forwarding holds the hop-by-hop routing. But choosing the correct path among different available multiple paths is most the important factor in the both case for a routing algorithm. Hence the most challenging factor is to determine a forwarding strategy which will provide the schedule for each node for transmission within the channel. In this research work we have tried to implement two forwarding strategies for the multi path multi radio WMN as the approximate solution for the above said problem. We have implemented Global State Routing (GSR) which will consider the packet forwarding concept and Aggregation Aware Layer 2 Routing (AAL2R) which considers the both concept i.e. both packet forwarding and packet aggregation. After the successful implementation the network performance has been measured by means of simulation study.
A distributed three hop routing protocol to increase theKamal Spring
Hybrid wireless networks combining the advantages of both mobile ad-hoc networks and infrastructure wireless networks have been receiving increased attention due to their ultra-high performance. An efficient data routing protocol is important in such networks for high network capacity and scalability. However, most routing protocols for these networks simply combine the ad-hoc transmission mode with the cellular transmission mode, which inherits the drawbacks of ad-hoc transmission. This paper presents a Distributed Three-hop Routing protocol (DTR) for hybrid wireless networks. To take full advantage of the widespread base stations, DTR divides a message data stream into segments and transmits the segments in a distributed manner. It makes full spatial reuse of a system via its high speed ad-hoc interface and alleviates mobile gateway congestion via its cellular interface. Furthermore, sending segments to a number of base stations simultaneously increases throughput and makes full use of widespread base stations. In addition, DTR significantly reduces overhead due to short path lengths and the elimination of route discovery and maintenance. DTR also has a congestion control algorithm to avoid overloading base stations. Theoretical analysis and simulation results show the superiority of DTR in comparison with other routing protocols in terms of throughput capacity, scalability and mobility resilience. The results also show the effectiveness of the congestion control algorithm in balancing the load between base stations.
Active Path Updation For Layered Routing (Apular) In Wireless Mesh Networkschetan1nonly
Routing is the major research issues in the Wireless Mesh Network (WMN). Ad-hoc networks routing protocols can be applied for WMN, but due to limited success & less efficiency there is need of more efficient routing protocols. In Infrastructure Wireless Mesh Routing Architecture (IWMRA) routing protocol, source node initiates a path establishing process whenever path breaks. This is not an ideal method in WMN where every nodes rather than source and destination in the path are motionless. One way of overcoming this is by initiating the local route repair by destination node. In this paper, we propose an active path updating procedure APULAR for quickly repair the broken path. Moreover, to improve throughput and to reduce the co-channel interference, we use multiple interface with multi channels. We are considering 4-hop as an interference range and will use fixed channel assignment within the mesh routers to reduce the inter flow interference. Our procedure is simulated in NS2 and compared with AODV – MI3 and APULAR-MI2, APULAR-MI3, APULAR-MI5. Simulation results show that our protocol performs better AODV in key performance metrics like packet delivery ratio, control overhead, average throughput and end-to-end delay.
1. A HYBRID NoC COMBINING SDM-BASED CIRCUIT SWITCHING WITH
PACKET SWITCHING FOR REAL-TIME APPLICATIONS
Angelo Kuti Lusala Jean-Didier Legat
Microelectronics laboratory, UCL Microelectronics laboratory, UCL
1348 Louvain-la-Neuve, Belgium 1348 Louvain-la-Neuve, Belgium
angelo.kutilusala@uclouvain.be Jean-Didier.Legat@uclouvain.be
Abstract—In this paper we propose a hybrid network-on-chip in the packet-switched sub-network. We use SDM technique
which combines Spatial Division Multiplexing “SDM”-based in order to increase path diversity in circuit-switched sub-
circuit switching and packet switching in order to efficiently network, thereby improving throughput and mitigating low
and separately handle streaming and best-effort traffics resource utilization which affects circuit-switched network.
generated by real-time applications. The SDM technique is In this way multiple connections can use channels in a given
used in circuit-switched sub-network in order to increase path direction; we then take advantage of the abundance of wires
diversity, thereby improving throughput and mitigating low resulting from the increasing integration density of CMOS
resource utilization, while packet-switched sub-network is kept circuits. SDM has been proposed as a valid alternative to
as simple as possible. In this way QoS is simply guaranteed
TDM [2]. SDM technique consists of allocating a sub-set of
without having to share resources, which often leads to a
complex design. The proposed hybrid router architecture has
channel wires to a given connection between a source node
been synthesized in FPGA and ASIC, and results show that a and destination node [2].
practical hybrid network-on-chip can then be built using the In the proposed architecture, the SDM variant used
proposed approach. consists in allocating more than one channel between
adjacent circuit-switched sub-routers. We then define SDM-
Keywords-SDM; TDM; QoS; circuit-switching; packet- Channel as a set of n-bit width sub-channels as shown in Fig.
switching; network-on-chip 1. Only one sub-channel in a SDM-channel is dedicated to a
connection. The SDM-based circuit-switched sub-router is
I. INTRODUCTION configured by the packet-switched sub-router.
The proposed hybrid-router architecture was
Multiprocessor System-on-Chips “MPSoCs” constitute implemented in both ASIC and FPGA technologies. Results
suitable platforms for real-time applications, since they offer show that increasing the number of sub-channels in a SDM-
high-power computing resources and parallelism that require Channel does not greatly affect the size and the maximum
real-time applications. In MPSoC platforms, the performance clock frequency of the proposed hybrid router. A practical
of applications strongly relies on the on-chip interconnection network-on-chip can then be built using the proposed router
network used to carry communications between cores in the architecture.
platform. Since real-time applications generate both The rest of the paper is organized as follows. Related
streaming and best effort traffics, the on-chip interconnection work is explored in section 2. Section 3 introduces the
network must provide quality of service “QoS” for streaming proposed architecture. Section 4 discusses synthesis results
traffic and data completion for best-effort traffic. Several of the proposed router architecture. Finally a conclusion is
networks-on-chips which handle both streaming and best- drawn in section 5.
effort traffics have been proposed in the literature; some of
them are Time Division Multiplexing “TDM”-based II. RELATED WORK
connection-oriented while others are connectionless-oriented Many hybrid Networks-on-Chips have been proposed in
and assign priority to traffic [3][6]. However, handling both the literature. In this paper we focus on those which combine
streaming and best-effort traffics in a network-on-chip by different switching techniques. In [3] ÆTHEREAL NoC is
sharing resources is very hard and often leads to a complex presented. It consists of two disjoint sub-networks: a
design with power consumption and area overhead [1]. Guaranteed Service “GS” sub-network and a Best-Effort
Since streaming traffic is well handled in a connection “BE” sub-network. The GS sub-network is TDM-based
oriented or circuit-switched network and best-effort traffic is connection-oriented while the BE sub-network is packet-
well handled in a connectionless oriented or packet-switched switched based. The BE sub-network is responsible for
network, we thus propose in this paper a hybrid network-on- configuring the GS sub-network. The reserved time slots are
chip which separately and efficiently handles both streaming used to carry streaming traffic while non-reserved time slots
and best-effort traffics. The proposed hybrid network are used to carry best-effort traffic. Store and forward flow
consists of two disjoint sub-networks, a SDM-based circuit- control is used in GS sub-network and wormhole is used in
switched sub-network and a packet-switched sub-network. BE sub-network, this implies the use of buffers in both GS
The streaming traffic is handled in the SDM-based circuit- and BE sub-networks. This often leads to complex design
switched sub-network while the best-effort traffic is handled with area and power consumption overhead [1][2]. In [4], a
978-1-4244-8971-8/10$26.00 c 2010 IEEE
2. technique called Hybrid Circuit Switching “HCS” is to a simple circuit-switched router or TDM connection-
presented; it consists of a circuit-switched network which oriented router.
intermingles circuit-switched flits with packet-switched flits. When a tile needs to send streaming traffic to another tile
A circuit-switched packet is immediately injected in the in the network, a path or connection must first be established
network behind the circuit setup request. If there is no between the two tiles. To establish the connection, the tile
unused resource, the circuit-switched packet is transformed source sends a setup best-effort packet to its packet-switched
to a packet-switched packet and is buffered; it will then keep sub-router. This setup packet reserves an available sub-
its new state until it is delivered. Although this technique can channel in each packet-switched sub-router crossed along its
reduce the circuit setup time overhead in the circuit-switched path from the source to destination. The packet-switched
network, it is still difficult to provide QoS. The NoC sub-router configures the attached SDM-based circuit-
presented in [5] is quite similar to the one presented in [4]. In switched sub-router by indicating the number identifier of
this NoC, a packet can use alternatively a circuit-switched the sub-channel to use for the concerned connection. When
and packet-switched sub-network. The authors claim that in the transaction of transferring streaming traffic is completed,
each router, traffic is split between the two sub-networks in each SDM-based circuit-switched sub-router along the path
such a way that the power and the performance metrics of notifies each attached packet-switched sub-router to release
the NoC are improved. With this technique it is still difficult the concerned sub-channel. When a tile needs to send best-
to provide QoS for streaming traffic. In [2] is presented one effort traffic, it directly sends a “Normal” best-effort packet
of the first works using SDM in a NoC in order to provide to the packet-switched sub-router.
QoS. This NoC covers only streaming traffic.
B. Packet- Switched sub-router
III. PROPOSED NETWORK ARCHITECTURE The Packet-switched sub-router is responsible for
handling best-effort traffic and configuring the attached
A. Router architecture SDM-based circuit-switched sub-router as shown in Fig. 1. It
The proposed router architecture consists of two major uses XY routing algorithm, with cut-through as control flow.
components as illustrated in Fig. 1: a packet-switched sub- We impose that packets coming from a given direction
router and a SDM-based circuit-switched sub-router. cannot return in the same direction. The packet-switched
sub-router has five bidirectional ports as shown in Fig. 1.
Routing is distributed so that up to five packets can be
simultaneously routed when they request different channels.
A best-effort packet consists of five fields. Its structure is
given in Fig. 2. Two bits indicating the type of the best-effort
packet, the source and destination address are 6-bits wide
since we consider a 7x7 mesh topology NoC. The sub-
channel number identifier is 3-bits wide, thus a SDM-
Channel can contain up to 7 sub-channels and the payload is
8-bits wide. The size of the best-effort packets varies
according to the number of sub-channels in a SDM-Channel.
Figure 2. Best-effort packet
Figure 1. Hybrid router architecture
We define three types of best-effort packets for the
The two sub-routers handle traffic independently. The proposed architecture:
SDM-based circuit-switched sub-router is configured by the - A setup best-effort packet, which is responsible for
packet-switched sub-router, while the SDM-based circuit- establishing paths for a streaming traffic through the circuit-
switched sub-router notifies the packet-switched when a switched sub-network between a source and destination. For
transaction of transferring streaming traffic is completed. As a setup best-effort packet, the value of the fields type and
seen previously, an SDM-Channel consists of a set of a given payload are respectively “10” and “00000000”.
number of sub-channels. Each sub-channel is n-bits wide and - An acknowledge “ACK” best-effort packet, which is
is identified by a number called “number identifier”. A generated when a setup packet reaches its destination. It is
connection can only acquire one sub-channel in a SDM- built by swapping the fields destination address and source
Channel. For example, for a SDM-Channel of five sub- address from the setup packet. Its fields type, sub-channel
channels, up to five connections can simultaneously use this number identifier and payload are respectively “01”, “000”
SDM-Channel. With the SDM approach, the router offers and “00000000”.
increased path diversity, improving the throughput compared
3. - A Normal best-effort packet, which carries best-effort channels reserved by this setup packet. The NACK signal in
payload. Its fields type and sub-channel number identifier are the packet-switched sub-router where the setup packet failed
respectively “11” and “000”. is equal to the sub-channel number identifier contained in
this setup packet. The NACK signal indicates to the previous
packet-switched sub-router the sub-channel to release. In the
previous packet-switched sub-router the NACK is equal to
the MSB of the reg_identifier.
Configuring the attached SDM-based circuit-switched
sub-router consists in indicating to each crossbar in the
SDM-based circuit-switched sub-router the number identifier
of the sub-channels to send in the output SDM-Channel.
C. SDM-Based Circuit- Switched sub-router
The SDM-based circuit-switched sub-router is
responsible for carrying streaming traffic. It has five
bidirectional ports. Four bidirectional ports are SDM-based
and are used to connect the sub-router with four adjacent
circuit-switched sub-routers and the fifth bidirectional port
which consists of a sub-channel is used to connect the sub-
router with the local tile as shown in Fig. 1. The SDM
channel consists of a given number of sub-channels. Each
sub-channel is N-bits wide. Streaming data is organized in
Figure 3. Packet-switched sub-router packets like cells in ATM. The streaming packet data unit
structure is shown in Fig. 4.
The packet-switched sub-router consists of input buffers,
link controllers and allocators as shown in Fig. 3. The input
buffers store incoming best-effort packets. The link
controller is responsible for reading packets in the attached
input buffer and deciding to which allocator to send the read Figure 4. Streaming packet data unit
packet according to the destination address. Since no packet
loss is allowed, the link controller keeps the read packet in a The SDM-based circuit-switched sub-router consists of
register until it receives a signal from the allocator indicating five crossbars and five header detectors. A crossbar and
that the packet is successfully sent to the output port. This header detectors are placed in each direction. The crossbar
strategy ensures that no packet is lost in the network. consists of multiplexers. Since crossbars are configured by
The allocators are responsible for writing best-effort the packet-switched allocators, the use of XY routing
packets to the input buffers of the next packet-switched sub- algorithm in the packet-switched sub-router, determines the
router and configuring the SDM-based circuit-switched sub- number of input ports of each crossbar. The crossbar in
router. They first check the type of the best-effort packet. If EAST direction can carry streaming traffic from either
the packet is an ACK or a Normal packet, then the allocator SDM-Channel from west or local tile sub-channel. The
directly sends it to the attached output link without crossbar in WEST direction has the same structure than the
modifying it. If the packet is a setup packet, then the one in EAST direction. The crossbar in NORTH, SOUTH
allocator reserves an available sub-channel in the SDM- and LOCAL can carry streaming data coming from four
Channel in the concerned direction, builds a new setup possible directions. Figure 5 gives the block diagram of the
packet by replacing the field sub-channel number of the crossbar in EAST direction and figure 6 shows its
incoming setup packet by the number identifier of the implementation using multiplexers. Figure 7 gives the block
reserved sub-channel. If the SDM-Channel has four sub- diagram of the crossbar in NORTH direction.
channels, then the number identifier of each sub-channel is
respectively 1, 2, 3 and 4.
The incoming sub-channel number identifier and the
outgoing sub-channel number identifier are concatenated and
stored in a register. The incoming sub-channel number
identifier is the MSB of this register while the outgoing sub-
channel number identifier is the LSB. This register is called
“reg_identifier”. This register helps to find the sub-channel
to release when a setup packet fails. When a setup packet Figure 5. Block Diagram Crossbar East Direction
fails to reserve a sub-channel in a packet-switched sub-
router, a negative acknowledge “NACK” signal is sent back The size of the crossbars depends on the number of input
and propagates to all previous packet-switched sub-routers ports. For a SDM- Channel consisted of three sub-channels,
crossed by this setup packet in order to release all sub- the size of crossbars in directions EAST and WEST is 5 x 3,
4. those in NORTH and SOUTH directions are 11x3 while the The increase of router area is mainly due to crossbars whose
size of the crossbar in local direction is 13x1. Signals “Sel1”, size varies according to the number of input ports. Synthesis
“Sel2” and “Sel3” are provided by the best-effort allocator. results show that the proposed hybrid router architecture can
Each sub-channel of the SDM output channel is connected to be used to build a practical network-on-chip.
a header detector.
TABLE I
ASIC SYNTHESIS RESULTS FOR THE ROUTER
Number of sub-channels Frequency Area Power
in a SDM-Channel GHz µm2 µW/MHz
3 2.8 36352 13.21
4 2.8 40743 14.28
5 2.8 44157 15
TABLE II
FPGA P&R RESULTS FOR THE ROUTER
Number of sub-channels Frequency Total Logic utilization
in a SDM-Channel MHz STRATIX III
3 179 1.4 %
4 164 1.7%
Figure 6. Detailed Crossbar East Direction
5 148 2%
V. CONCLUSION
In this paper, a hybrid network-on-chip architecture
which combines a SDM-based circuit switching with packet
switching for real-time applications is proposed. The
proposed hybrid router architecture efficiently and separately
handles streaming and best-effort traffics respectively in a
SDM-based circuit-switched sub-router and packet-switched
sub-router. The SDM approach is used to allow path
diversity, thereby mitigating low resource utilization in
circuit switching, and improving throughput. QoS is then
easily provided. The packet-switched sub-router is kept as
Figure 7. Block Diagram Crossbar North Direction simple as possible. The proposed router architecture was
implemented in Verilog and synthesized in both ASIC and
The header detector extracts the header of the packet FPGA. Synthesis results show that a practical network-on-
streaming data; if the header is equal to 2 then a signal is sent chip can be built using the proposed approach.
to the best-effort allocator attached to the crossbar to release
the associated sub-channel. The SDM-based circuit-switched REFERENCES
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