Showing papers on "Geographic routing published in 2010"

Routing for disruption tolerant networks: taxonomy and design

Abstract: Communication networks, whether they are wired or wireless, have traditionally been assumed to be connected at least most of the time. However, emerging applications such as emergency response, special operations, smart environments, VANETs, etc. coupled with node heterogeneity and volatile links (e.g. due to wireless propagation phenomena and node mobility) will likely change the typical conditions under which networks operate. In fact, in such scenarios, networks may be mostly disconnected, i.e., most of the time, end-to-end paths connecting every node pair do not exist. To cope with frequent, long-lived disconnections, opportunistic routing techniques have been proposed in which, at every hop, a node decides whether it should forward or store-and-carry a message. Despite a growing number of such proposals, there still exists little consensus on the most suitable routing algorithm(s) in this context. One of the reasons is the large diversity of emerging wireless applications and networks exhibiting such "episodic" connectivity. These networks often have very different characteristics and requirements, making it very difficult, if not impossible, to design a routing solution that fits all. In this paper, we first break up existing routing strategies into a small number of common and tunable routing modules (e.g. message replication, coding, etc.), and then show how and when a given routing module should be used, depending on the set of network characteristics exhibited by the wireless application. We further attempt to create a taxonomy for intermittently connected networks. We try to identify generic network characteristics that are relevant to the routing process (e.g., network density, node heterogeneity, mobility patterns) and dissect different "challenged" wireless networks or applications based on these characteristics. Our goal is to identify a set of useful design guidelines that will enable one to choose an appropriate routing protocol for the application or network in hand. Finally, to demonstrate the utility of our approach, we take up some case studies of challenged wireless networks, and validate some of our routing design principles using simulations.

TPGF: geographic routing in wireless multimedia sensor networks

Abstract: In this paper, we propose an efficient Two-Phase geographic Greedy Forwarding (TPGF) routing algorithm for WMSNs TPGF takes into account both the requirements of real time multimedia transmission and the realistic characteristics of WMSNs It finds one shortest (near-shortest) path per execution and can be executed repeatedly to find more on-demand shortest (near-shortest) node-disjoint routing paths TPGF supports three features: (1) hole-bypassing, (2) the shortest path transmission, and (3) multipath transmission, at the same time TPGF is a pure geographic greedy forwarding routing algorithm, which does not include the face routing, eg, right/left hand rules, and does not use planarization algorithms, eg, GG or RNG This point allows more links to be available for TPGF to explore more routing paths, and enables TPGF to be different from many existing geographic routing algorithms Both theoretical analysis and simulation comparison in this paper indicate that TPGF is highly suitable for multimedia transmission in WMSNs

GeoDTN+Nav: Geographic DTN Routing with Navigator Prediction for Urban Vehicular Environments

Abstract: Position-based routing has proven to be well suited for highly dynamic environment such as Vehicular Ad Hoc Networks (VANET) due to its simplicity. Greedy Perimeter Stateless Routing (GPSR) and Greedy Perimeter Coordinator Routing (GPCR) both use greedy algorithms to forward packets by selecting relays with the best progress towards the destination or use a recovery mode in case such solutions fail. These protocols could forward packets efficiently given that the underlying network is fully connected. However, the dynamic nature of vehicular network, such as vehicle density, traffic pattern, and radio obstacles could create unconnected networks partitions. To this end, we propose GeoDTN+Nav, a hybrid geographic routing solution enhancing the standard greedy and recovery modes exploiting the vehicular mobility and on-board vehicular navigation systems to efficiently deliver packets even in partitioned networks. GeoDTN+Nav outperforms standard geographic routing protocols such as GPSR and GPCR because it is able to estimate network partitions and then improves partitions reachability by using a store-carry-forward procedure when necessary. We propose a virtual navigation interface (VNI) to provide generalized route information to optimize such forwarding procedure. We finally evaluate the benefit of our approach first analytically and then with simulations. By using delay tolerant forwarding in sparse networks, GeoDTN+Nav greatly increases the packet delivery ratio of geographic routing protocols and provides comparable routing delay to benchmark DTN algorithms.

Energy-aware routing in data center network

Abstract: The goal of data center network is to interconnect the massive number of data center servers, and provide efficient and fault-tolerant routing service to upper-layer applications. To overcome the problem of tree architecture in current practice, many new network architectures are proposed, represented by Fat-Tree, BCube, and etc. A consistent theme in these new architectures is that a large number of network devices are used to achieve 1:1 oversubscription ratio. However, at most time, data center traffic is far below the peak value. The idle network devices will waste significant amount of energy, which is now a headache for many data center owners.In this paper, we discuss how to save energy consumption in high-density data center networks in a routing perspective. We call this kind of routing energy-aware routing. The key idea is to use as few network devices to provide the routing service as possible, with no/little sacrifice on the network performance. Meanwhile, the idle network devices can be shutdown or put into sleep mode for energy saving. We establish the model of energy-aware routing in data center network, and design a heuristic algorithm to achieve the idea. Our simulation in typical data center networks shows that energy-aware routing can effectively save power consumed by network devices.

Replication routing in DTNs: a resource allocation approach

Abstract: Routing protocols for disruption-tolerant networks (DTNs) use a variety of mechanisms, including discovering the meeting probabilities among nodes, packet replication, and network coding. The primary focus of these mechanisms is to increase the likelihood of finding a path with limited information, and so these approaches have only an incidental effect on such routing metrics as maximum or average delivery delay. In this paper, we present rapid, an intentional DTN routing protocol that can optimize a specific routing metric such as the worst-case delivery delay or the fraction of packets that are delivered within a deadline. The key insight is to treat DTN routing as a resource allocation problem that translates the routing metric into per-packet utilities that determine how packets should be replicated in the system. We evaluate rapid rigorously through a prototype deployed over a vehicular DTN testbed of 40 buses and simulations based on real traces. To our knowledge, this is the first paper to report on a routing protocol deployed on a real outdoor DTN. Our results suggest that rapid significantly outperforms existing routing protocols for several metrics. We also show empirically that for small loads, RAPID is within 10% of the optimal performance.

Energy-Efficient Beaconless Geographic Routing in Wireless Sensor Networks

Abstract: Geographic routing is an attractive localized routing scheme for wireless sensor networks (WSNs) due to its desirable scalability and efficiency. Maintaining neighborhood information for packet forwarding can achieve a high efficiency in geographic routing, but may not be appropriate for WSNs in highly dynamic scenarios where network topology changes frequently due to nodes mobility and availability. We propose a novel online routing scheme, called Energy-efficient Beaconless Geographic Routing (EBGR), which can provide loop-free, fully stateless, energy-efficient sensor-to-sink routing at a low communication overhead without the help of prior neighborhood knowledge. In EBGR, each node first calculates its ideal next-hop relay position on the straight line toward the sink based on the energy-optimal forwarding distance, and each forwarder selects the neighbor closest to its ideal next-hop relay position as the next-hop relay using the Request-To-Send/Clear-To-Send (RTS/CTS) handshaking mechanism. We establish the lower and upper bounds on hop count and the upper bound on energy consumption under EBGR for sensor-to-sink routing, assuming no packet loss and no failures in greedy forwarding. Moreover, we demonstrate that the expected total energy consumption along a route toward the sink under EBGR approaches to the lower bound with the increase of node deployment density. We also extend EBGR to lossy sensor networks to provide energy-efficient routing in the presence of unreliable communication links. Simulation results show that our scheme significantly outperforms existing protocols in wireless sensor networks with highly dynamic network topologies.

Backpressure-based routing protocol for DTNs

Abstract: In this paper we consider an alternative, highly agile In this paper we consider an alternative, highly agile approach called backpressure routing for Delay Tolerant Networks (DTN), in which routing and forwarding decisions are made on a per-packet basis. Using information about queue backlogs, random walk and data packet scheduling nodes can make packet routing and forwarding decisions without the notion of end-to-end routes. To the best of our knowledge, this is the first ever implementation of dynamic backpressure routing in DTNs. Simulation results show that the proposed approach has advantages in terms of DTN networks.

Network coding-aware routing in wireless networks

Abstract: A recent approach--COPE, presented by Katti et al. (Proc. ACM SIGCOMM 2006, pp. 243-254)--for improving the throughput of unicast traffic in wireless multihop networks exploits the broadcast nature of the wireless medium through opportunistic network coding. In this paper, we analyze throughput improvements obtained by COPE-type network coding in wireless networks from a theoretical perspective. We make two key contributions. First, we obtain a theoretical formulation for computing the throughput of network coding on any wireless network topology and any pattern of concurrent unicast traffic sessions. Second, we advocate that routing be made aware of network coding opportunities rather than, as in COPE, being oblivious to it. More importantly, our model considers the tradeoff between routing flows close to each other for utilizing coding opportunities and away from each other for avoiding wireless interference. Our theoretical formulation provides a method for computing source-destination routes and utilizing the best coding opportunities from available ones so as to maximize the throughput. We handle scheduling of broadcast transmissions subject to wireless transmit/receive diversity and link interference in our optimization framework. Using our formulations, we compare the performance of traditional unicast routing and network coding with coding-oblivious and coding-aware routing on a variety of mesh network topologies, including some derived from contemporary mesh network testbeds. Our evaluations show that a route selection strategy that is aware of network coding opportunities leads to higher end-to-end throughput when compared to coding-oblivious routing strategies.

Secure Routing in Wireless Sensor Networks.

Abstract: This research addresses communication security in the highly constrained wireless sensor environment. The goal of the research is twofold: (1) to develop a key management scheme that provides these constrained systems with the basic security requirements and evaluate its effectiveness in terms of scalability, efficiency, resiliency, connectivity, and flexibility, and (2) to implement this scheme on an appropriate routing platform and measure its efficiency. The proposed key management scheme is called Hierarchical Key Establishment Scheme (HIKES). In HIKES, the base station, acting as the central trust authority, empowers randomly selected sensors to act as local trust authorities, authenticating on its behalf the cluster members and issuing to them all secret keys necessary to secure their communications. HIKES uses a novel key escrow scheme that enables any sensor node selected as a cluster head to generate all the cryptographic keys needed to authenticate other sensors within its cluster. This scheme localizes secret key issuance and reduces the communication cost with the base station. The key escrow scheme also provides the HIKES with as large an addressing mechanism as needed. HIKES also provides a one-step broadcast authentication mechanism. HIKES provides entity authentication to every sensor in the network and is robust against most known attacks. We propose a hierarchical routing mechanism called Secure Hierarchical Energy-Efficient Routing protocol (SHEER). SHEER implements HIKES, which provides the communication security from the inception of the network. SHEER uses a probabilistic broadcast mechanism and a three-level hierarchical clustering architecture to improve the network energy performance and increase its lifetime. Simulation results have shown that HIKES provides an energy-efficient and scalable solution to the key management problem. Cost analysis shows that HIKES is computationally efficient and has low storage requirement. Furthermore, high degree of address flexibility can be achieved in HIKES. Therefore, this scheme meets the desired criteria set forth in this work. Simulation studies also show that SHEER is more energy-efficient and has better scalability than the secure version of LEACH using HIKES.

The Deployment of a Smart Monitoring System Using Wireless Sensor and Actuator Networks

Abstract: In this paper, we explore the implementation of a smart monitoring system over a wireless sensor network, with particular emphasis on the creation of a solid routing infrastructure through the Routing Protocol for Low- power and lossy networks (RPL), whose definition is currently being discussed within the IETF ROLL working group. Our framework is based on a very lightweight implementation of the REpresentational State Transfer (REST) paradigm by means of a binary web service, and on a publish/subscribe mechanism, whereby every node makes a set of resources (e.g., environmental sensors) available to interested parties. Limited to the effectiveness in creating the routing structure, we provide a performance evaluation of RPL through an experimental campaign, aimed at showing how RPLs key parameters affect the performance of routing in a smart grid scenario.

SADV: Static-Node-Assisted Adaptive Data Dissemination in Vehicular Networks

Abstract: Vehicular networks have recently attracted great interest in the research community, and multihop data dissemination has become an important issue. To improve data-delivery performance, we propose deploying static nodes at road intersections to help relay data. In this paper, we present SADV, which is a static-node assisted adaptive data-dissemination protocol for vehicular networks. With the assistance of static nodes at intersections, a packet is forwarded to the static node when there are no vehicles available to deliver the packets along the optimal path. The static node is able to store the packet and transmit it when the optimal delivery path becomes available. In addition, we let adjacent static nodes measure the delay of forwarding data between each other in real time so that the routing decision that is made at static nodes can adapt to the changing vehicle densities. Moreover, a multipath routing mechanism is also adopted in SADV, which is effective in reducing the data-delivery delay. Our simulation results show that SADV outperforms other multihop data dissemination protocols, particularly under median or low vehicle density where the network is frequently partitioned. In this paper, we also present some heuristic deployment strategies to maximize SADV performance under partial deployment of static nodes and analyze them by simulations.

Hierarchical geographic multicast routing for wireless sensor networks

Abstract: Wireless sensor networks comprise typically dense deployments of large networks of small wireless capable sensor devices. In such networks, multicast is a fundamental routing service for efficient data dissemination required for activities such as code updates, task assignment and targeted queries. In particular, efficient multicast for sensor networks is critical due to the limited energy availability in such networks. Multicast protocols that exploit location information available from GPS or localization algorithms are more efficient and robust than other stateful protocols as they avoid the difficulty of maintaining distributed state (multicast tree). Since localization is typically already required for sensing applications, this location information can simply be reused for optimizing multicast performance at no extra cost. Recently, two protocols were proposed to optimize two orthogonal aspects of location-based multicast protocols: GMR (Sanchez et al. GMR: Geographic multicast routing for wireless sensor networks. In Proceedings of the IEEE SECON, 2006) improves the forwarding efficiency by exploiting the wireless multicast advantage but it suffers from scalability issues when dealing with large sensor networks. On the other hand, HRPM (Das et al. Distributed hashing for scalable multicast in wireless ad hoc networks. IEEE TPDS 47(4):445---487, 2007) reduces the encoding overhead by constructing a hierarchy at virtually no maintenance cost via the use of geographic hashing but it is energy-inefficient due to inefficacies in forwarding data packets. In this paper, we present HGMR (hierarchical geographic multicast routing), a new location-based multicast protocol that seamlessly incorporates the key design concepts of GMR and HRPM and optimizes them for wireless sensor networks by providing both forwarding efficiency (energy efficiency) as well as scalability to large networks. Our simulation studies show that: (i) In an ideal environment, HGMR incurs a number of transmissions either very close to or lower than GMR, and, at the same time, an encoding overhead very close to HRPM, as the group size or the network size increases. (ii) In a realistic environment, HGMR, like HRPM, achieves a Packet Delivery Ratio (PDR) that is close to perfect and much higher than GMR. Further, HGMR has the lowest packet delivery latency among the three protocols, while incurring much fewer packet transmissions than HRPM. (iii) HGMR is equally efficient with both uniform and non-uniform group member distributions.

Method and system for extending routing domain to non-routing end stations

Abstract: A system is provided for facilitating assignment of a virtual routing node identifier to a non-routing node. During operation, the system assigns to a non-routing node coupled to a switch a virtual routing node identifier unique to the non-routing node. In addition, the system communicates reachability information corresponding to the virtual routing node identifier to other switches in the network.

Some Results on Greedy Embeddings in Metric Spaces

Abstract: Geographic Routing is a family of routing algorithms that uses geographic point locations as addresses for the purposes of routing. Such routing algorithms have proven to be both simple to implement and heuristically effective when applied to wireless sensor networks. Greedy Routing is a natural abstraction of this model in which nodes are assigned virtual coordinates in a metric space, and these coordinates are used to perform point-to-point routing. Here we resolve a conjecture of Papadimitriou and Ratajczak that every 3-connected planar graph admits a greedy embedding into the Euclidean plane. This immediately implies that all 3-connected graphs that exclude K 3,3 as a minor admit a greedy embedding into the Euclidean plane. We also prove a combinatorial condition that guarantees nonembeddability. We use this result to construct graphs that can be greedily embedded into the Euclidean plane, but for which no spanning tree admits such an embedding.

Source-Location Privacy through Dynamic Routing in Wireless Sensor Networks

Abstract: Wireless sensor networks (WSNs) have the potential to be widely used in many areas for unattended event monitoring. Mainly due to lack of a protected physical boundary, wireless communications are vulnerable to unauthorized interception and detection. Privacy is becoming one of the major issues that jeopardize the successful deployment of wireless sensor networks. While confidentiality of the message can be ensured through content encryption, it is much more difficult to adequately address the source-location privacy. For WSNs, source-location privacy service is further complicated by the fact that the sensor nodes consist of low-cost and low-power radio devices, computationally intensive cryptographic algorithms and large scale broadcasting-based protocols are not suitable for WSNs. In this paper, we propose source-location privacy schemes through routing to randomly selected intermediate node(s) before the message is transmitted to the SINK node. We first describe routing through a single a single randomly selected intermediate node away from the source node. Our analysis shows that this scheme can provide great local source-location privacy. We also present routing through multiple randomly selected intermediate nodes based on angle and quadrant to further improve the global source location privacy. While providing source-location privacy for WSNs, our simulation results also demonstrate that the proposed schemes are very efficient in energy consumption, and have very low transmission latency and high message delivery ratio. Our protocols can be used for many practical applications.

Using wireless sensor networks to support intelligent transportation systems

Abstract: In this paper we propose a system architecture for enabling mobile nodes to query a largely deployed wireless sensor network in an intelligent transportation system scenario. We identify three different types of nodes in the network: mobile sinks (i.e. the nodes moving and querying the WSN), vice-sinks (i.e. nodes able to communicate directly with mobile sinks) and ordinary sensor nodes (i.e. nodes sensing a phenomenon and communicating in a multihop fashion). We present protocols and algorithms specifically tailored to such a scenario, in particular at the MAC and network layers. Such a reference architecture well covers situations in which WSNs deployed in a parking place or along a road, provide to cars information on the conditions of the surrounding environment. We introduce and analyse a simple geographic routing protocol and two different load balancing techniques. The performance of the proposed solutions is evaluated through extensive simulations. The simple geographic routing is compared to load balancing techniques. Results support the capability of the proposed solutions to enable the introduction of novel intelligent transportation system applications.

Mesh routing method and mesh routing apparatus in beacon enabled wireless AD-HOC networks

Abstract: There is provided a mesh routing method in beacon-enabled wireless AD-HOC networks that includes: broadcasting, by nodes constituting a wireless AD-HOC network, a beacon message loading neighbor node information on a beacon payload; managing, by a node receiving the broadcasted beacon message, its own neighbor node table by extracting the neighbor node information loaded on the beacon payload; and performing, by a source node attempting to transmit data or commands, mesh routing on the basis of its own neighbor node table.

A power-efficient all-optical on-chip interconnect using wavelength-based oblivious routing

Abstract: We present an all-optical approach to constructing data networks on chip that combines the following key features: (1) Wavelength-based routing, where the route followed by a packet depends solely on the wavelength of its carrier signal, and not on information either contained in the packet or traveling along with it. (2) Oblivious routing, by which the wavelength (and thus the route) employed to connect a source-destination pair is invariant for that pair, and does not depend on ongoing transmissions by other nodes, thereby simplifying design and operation. And (3) passive optical wavelength routers, whose routing pattern is set at design time, which allows for area and power optimizations not generally available to solutions that use dynamic routing. Compared to prior proposals, our evaluation shows that our solution is significantly more power efficient at a similar level of performance.

On Joint Frequency and Power Allocation in a Cross-Layer Protocol for Underwater Acoustic Networks

Abstract: Path loss in an underwater acoustic channel depends not only on the transmission distance, but also on the signal frequency. As a result, the useful bandwidth decreases with distance, a feature not normally present in terrestrial radio networks. This fact motivates the use of multihop communications in an acoustic network, and strongly influences its design, since the same set of protocols will exhibit different performance when operating in a different frequency range. Multihop transmission is considered for large area coverage in acoustic networks, with an eye towards efficient power and bandwidth allocation. Power control is used as a practical means of optimizing the overall performance across the physical, medium access control (MAC) and routing layers. A geographic routing technique, called the focused beam routing (FBR), which requires each node to know only its own location and that of the final destination, is coupled with the distance aware collision avoidance protocol, which regulates the channel access. Results show that the average energy per bit consumption is reduced by adjusting the power, center frequency, and bandwidth in accordance with the network node density. Specifically, as the density increases, greater bandwidths offer per-hop energy reduction as well as a reduced packet collision rate.

Trust Management for Encounter-Based Routing in Delay Tolerant Networks

Abstract: We propose and analyze a class of trust management protocols for encounter-based routing in delay tolerant networks (DTNs). The underlying idea is to incorporate trust evaluation in the routing protocol, considering not only quality-of-service (QoS) trust properties (connectivity) but also social trust properties (honesty and unselfishness) to evaluate other nodes encountered. Two versions of trust management protocols are considered: an equal-weight QoS and social trust management protocol (called trust-based routing) and a QoS only trust management protocol (called connectivity-based routing). By utilizing a stochastic Petri net model describing a DTN behavior, we analyze the performance characteristics of these two routing protocols in terms of message delivery ratio, latency, and message overhead. We also perform a comparative performance analysis with epidemic routing for a DTN consisting of heterogeneous mobile nodes with vastly different social and networking behaviors. The results indicate that trust-based routing approaches the ideal performance of epidemic routing in delivery ratio, while connectivity-based routing approaches the ideal performance in message delay of epidemic routing, especially as the percentage of selfish and malicious nodes present in the DTN system increases. By properly selecting weights associated with QoS and social trust metrics for trust evaluation, our trust management protocols can approximate the ideal performance obtainable by epidemic routing in delivery ratio and message delay without incurring high message overhead.

Location Assisted Routing Techniques for Power Line Communication in Smart Grids

Abstract: Smart Grid collectively refers to various visions of how energy generation, distribution, and consumption should be managed to overcome many of the shortcomings of today's electricity grids and to sustain our ever more electricity dependent societies. One important enabling component of Smart Grid will be a fine-grained and reliable communications infrastructure that links together the many elements of the grid. Since by definition all these elements are connected to power lines, power line communications (PLC) technology is a natural candidate to build parts of such an infrastructure. In this paper, we consider the use of PLC in low- and medium-voltage distribution grids to connect network nodes (e.g., meters, actuators, sensors) through multihop transmission. In particular, we address the problem of routing of unicast messages making use of the stationarity of nodes. To this end, we motivate and investigate the application of geographic routing protocols and gauge their performance with respect to energy consumption and transmission delay.

Systems and Methods for Determining a Destination Location from a Communication

Abstract: Systems and methods for determining a destination location from a communication are described. One embodiment of a method includes receiving electronic communications data from a mobile communications device, at a computing device. The electronic communications data is parsed to identify a partial address term of interest related to the destination location in the electronic communications data. A position of the destination location is determined from the partial address term of interest. Routing data of a vehicle from a current location of the vehicle to the destination location is determined and provided to a user of the vehicle.

Geo-opportunistic routing for vehicular networks [Topics in Automotive Networking]

Abstract: Road topology information has recently been used to assist geographic routing in urban vehicular environments to improve overall routing performance. However, the unreliable nature of wireless channels due to motion and obstructions still makes road topology assisted geographic routing challenging. In this article we begin by reviewing conventional road topology assisted geographic routing protocols, and investigate the robust routing protocols that address and help overcome the unreliable wireless channels. We then present topology-assisted geo-opportunistic routing that incorporates topology assisted geographic routing with opportunistic forwarding. That is, the routing protocol exploits the simultaneous packet receptions induced by the broadcast nature of the wireless medium and performs opportunistic forwarding via a subset of neighbors that have received the packet correctly. Our simulation results confirm TO-GO's superior robustness to channel errors and collisions compared to conventional topology-assisted geographic routing protocols.

Routing Approaches in Delay Tolerant Networks: A Survey

Abstract: Delay Tolerant Networks (DTNs) have evolved from Mobile Ad Hoc Networks (MANET). It is a network, where contemporaneous connectivity among all nodes doesn’t exist. This leads to the problem of how to route a packet from one node to another, in such a network. This problem becomes more complex, when the node mobility also is considered. The researchers have attempted to address this issue for over a decade. They have found that communication is possible in such a challenged network. The design of routing protocol for such networks is an important issue. This work surveys the literature and classifies the various routing approaches.

Infrastructure-assisted geo-routing for cooperative vehicular networks

Abstract: Cooperative vehicular systems require the design of reliable and efficient multi-hop networking protocols to achieve their foreseen benefits. Although many geo-routing protocols have been proposed in the literature, few contributions have analysed the benefits that road side infrastructure units could provide to successfully route data from source to destination. In this context, this paper proposes a novel infrastructure-assisted routing approach designed to improve the end-to-end performance, range and operation of multi-hop vehicular communications by exploiting the reliable interconnection of infrastructure units. The conducted investigation shows that the proposed infrastructure-assisted routing approach achieves its objectives, and reduces the routing overhead compared to other greedy position-based geo-routing protocols. Finally, the paper shows that to obtain the maximum benefits from the proposed infrastructure-assisted routing approach, optimal infrastructure deployment strategies must be further investigated.

Destination-based adaptive routing on 2D mesh networks

Abstract: The choice of routing algorithm plays a vital role in the performance of on-chip interconnection networks. Adaptive routing is appealing because it offers better latency and throughput than oblivious routing, especially under non-uniform and bursty traffic. The performance of an adaptive routing algorithm is determined by its ability to accurately estimate congestion in the network. In this regard, maintaining global congestion information using a separate monitoring network offers better congestion visibility into distant parts of the network than solutions relying only on local congestion state. However, the main challenge in designing such routing schemes is to keep the logic and bandwidth overhead as low as possible to fit into the tight power, area and delay budgets of on-chip routers. In this paper, we propose a minimal destination-based adaptive routing strategy (DAR) where every node estimates the delay to every other node in the network, and routing decisions are based on these per-destination delay estimates. DAR outperforms Regional Congestion Awareness (RCA) [7], the best previously known adaptive routing algorithm that uses non-local congestion knowledge. This is because the per-destination delay estimates in DAR are more accurate and not corrupted by congestion on links outside the admissible routing paths to the destination. We show that DAR outperforms minimal adaptive routing by up to 65% and RCA by up to 41% in terms of latency on SPLASH-2 benchmarks. It also outperforms these algorithms in latency and throughput under synthetic traffic patterns on both 8x8 and 16x16 mesh topologies.