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OTIS-based architectures appear to have the potential to be an interesting option for future generations of multiprocessing systems. In this paper, we propose a new adaptive unicast routing algorithm and four software-based (unicast-based) broadcast algorithms for the wormhole switched OTI S-hypercube. We then present an empirical performance evaluation of these algorithms in OTIS-hypercube for different topologies, message length and traffic loads. © 2008 IEEE  

Few works has been focused on the problem of joint distributed data compression and network coding. In this paper we give some examples showing the advantage of broadcast nature of wireless environment as a basis for joint codes design. Also we show that joint coding is possible in the case of multiple unicasts. The idea of this paper can be exploited in an opportunistic manner. Actually, the foundation of our idea is nothing but combining opportunistic network coding (COPE) and distributed source coding using syndromes (DISCUS) for wireless applications. © 2009 IEEE  

In this study, the authors extend the concept of relay channel with orthogonal components to define a class of symmetric relay networks with orthogonal components named symmetric orthogonal relay network. In the defined network, the channels diverge from each node sender use different frequency bands whereas the channels converge to each node receiver use the same frequency band. This structure is very well understood in half-duplex transmission systems where the relays cannot send and receive at the same time or over the same frequency band. The authors show that the unicast capacity of the defined network is equal to the cut-set bound. In the achievability proof, the authors take advantage... 

Networks-on-Chip (NoCs for short) are known as the most scalable and reliable on-chip communication architectures for multi-core SoCs with tens to hundreds IP cores. Proper mapping the IP cores on NoC tiles (or assigning threads to cores in chip multiprocessors) can reduce end-to-end delay and energy consumption. While almost all previous works on mapping consider higher priority for the application's flows with higher required bandwidth, a mapping strategy, presented in this paper, is introduced that considers multicast communication flows in addition to the normal unicast flows. To this end, multicast and unicast traffic flows are first characterized in terms of some new metrics which are... 

The paper proposes a scalable wavelength-switched optical NoC, named as SWS-ONoC. The proposed architecture is built upon a novel all-optical router which passively routes optical data streams based on their wavelengths. Utilizing wavelength routing method, SWS-ONoC eliminates electrical transactions for optical resource reservation and hence, reduces latency and area overheads of the electrical units. The proposed architecture benefits from Wavelength Division Multiplexing (WDM) scheme to efficiently route multicast optical packets concurrent with unicast data streams. Performing a series of simulation-based experiments, we study efficiency of the proposed architecture, its power and energy... 

Networks-on-Chip (NoCs for short) are known as the most scalable and reliable on-chip communication architectures for multi-core SoCs with tens to hundreds IP cores. Proper mapping the IP cores on NoC tiles (or assigning threads to cores in chip multiprocessors) can reduce end-to-end delay and energy consumption. While almost all previous works on mapping consider higher priority for the application's flows with higher required bandwidth, a mapping strategy, presented in this paper, is introduced that considers multicast communication flows in addition to the normal unicast flows. To this end, multicast and unicast traffic flows are first characterized in terms of some new metrics which are... 

Exponential backoff is an intrinsic feature of MAC-layer standards of most types of ad hoc networks. It leads to random access channels with memory. In this paper we propose a new network coding-based packet forwarding scheme suitable for multiple unicast scenarios in downlink direction of a wireless network. The wireless nodes as well as the access point attempt to access the channel, based on slotted Aloha with exponential backoff. In the proposed scheme we convert multiple unicast scenario to a combination of several anycast and a multicast scenarios. By proposing an open multiclass queueing network, we are able to derive the maximum stable download throughput of the network. The... 

In this paper, we propose a new packet routing scheme, i.e., a combined digital and analog network coding scheme (DNC-ANC) suitable for multiple unicast scenario. In this respect, we consider a random access WLAN comprised of single and multi-hop unicast sessions. Then we modify the MAC scheme in order to enable ANC. In order to evaluate the effect of the proposed DNC-ANC scheme analytically, we employ an open queueing network and map the details of MAC as well as routing schemes onto its suitable parameters. By writing the corresponding traffic equations and applying the stability condition, we are able to find the maximum stable throughput for the considered scenario. Finally, we will show... 

Broadcast is among the most primitive collective communication operations of any interconnection network. Broadcast algorithms for the mesh topology have been widely reported in the literature. However, most existing algorithms have been studied in one-port and within limited conditions, such as light traffic loads. In contrast, this study simulates the broadcast operations, taking into account a wide range of traffic loads. Also, the performance evaluation of meshes in the presence of unicast and broadcast traffic is presented in this paper. To the best of our knowledge, this study is the first to consider the issue of broadcast latency at both the network and node levels. A new model for... 

In this study, the authors propose an analytical model to evaluate the maximum stable throughput for unicast services in vehicular ad hoc networks. In this respect, the authors employ two queueing networks (QNs) to model the mobility patterns of the vehicles as well as the multi-hop packet transmission scenario. In the proposed model, the authors map the features of IEEE 802.11, as well as the details of multi-hop packet transmission, regarding the dynamic status of vehicles, onto suitable parameters of the QNs. In the authors' modelling approach, they take the details of MAC and routing schemes into account by classifying the vehicles based on their mobility patterns and considering their... 

We consider the problem of determining throughput of one-hop unicast transmissions in ad hoc wireless networks. We consider an interference-limited scenario in which wireless links between different nodes are modeled by independently and identically distributed random variables. The main decoding challenge for receive nodes is due to interference of nonintended concurrent transmissions. In this scenario, we consider a heuristic one-hop transmission strategy based on activating source-destination pairs with strongest direct links and forcing other pairs to be silent. We present a closed-form expression for throughput scaling of such strategy, for a completely general channel power... 

This paper proposes a novel all-optical router as a building block for a scalable wavelength-switched optical NoC. The proposed optical router, named as AOR, performs passive routing of optical data streams based on their wavelengths. Utilizing wavelength routing method, AOR eliminates the need for electrical resource reservation and the corresponding latency and area overheads. Taking advantage of Wavelength Division Multiplexing (WDM) technique, the proposed architecture is capable of data multicasting, concurrent with unicast data transmission, with high bandwidth and low power dissipation, without imposing noticeable area and latency overheads. Comparing AOR against previously proposed... 

Several unicast and multicast routing protocols have been presented for MPSoCs. Multicast protocols in NoCs are used for cache coherency in distributed shared memory systems, replication, barrier synchronization, or clock synchronization. Unicast routing algorithms are not suitable for multicast, as they increase traffic, congestion and deadlock probability. Famous multicast schemes such as tree-based and path-based schemes have been proposed originally for multicomputers and recently adapted to NoCs. In this paper, we propose a switch tree-based multicast scheme, called STBA. This method supports tree construction with a minimum number of routers. Our evaluation results reveal that, for... 

Different attacks on routing protocols in ad hoc networks occur that one of the most dangerous types is called wormhole attack. This attack happens with the assistance of at least two or more malicious nodes. In this attack nodes create a private tunnel which if a packet comes to one of them, it will be guided to other pair of these malicious nodes by this tunnel and that node broadcasts it into network. This action provides a short connection in the network that is controlled by these malicious nodes. Hence they control all Packets that come to them and threaten the security of data within packets or delete them. Totally, what a wormhole does is an incorrect understanding of network... 

Different attacks on routing protocols in ad hoc networks occur that one of the most dangerous types is called wormhole attack. This attack happens with the assistance of at least two or more malicious nodes. In this attack nodes create a private tunnel which if a packet comes to one of them, it will be guided to other pair of these malicious nodes by this tunnel and that node broadcasts it into network. This action provides a short connection in the network that is controlled by these malicious nodes. Hence they control all Packets that come to them and threaten the security of data within packets or delete them. Totally, what a wormhole does is an incorrect understanding of network... 

In this paper, we propose a new analytical model for stable throughput evaluation of wireless network coding. In this new approach we consider the arrival and departure rates in and from the wireless nodes, respectively, in steady state. Our analytical model is founded on a multi-class open queueing network. In this model, we include two basic processes of network coding, i.e., packets combination and packets multicasting, in a suitable manner considering the constraints of the queueing networks. In this respect, we consider the coded packets as new classes of customers. By solving the related traffic equations and applying the stability condition, we compute the maximum stable throughput,...