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This paper considers the problem of routing packets across a multi-hop wireless network while ensuring throughput optimality. One of the main challenges in the design of throughput optimal routing policies is identifying appropriate and universal Lyapunov functions with negative expected drift. The few well-known throughput optimal routing policies in the literature are constructed using simple quadratic...
Dense deployments of wireless local area networks (WLANs) are fast becoming a permanent feature of all developed cities around the world. While this increases capacity and coverage, the problem of increased interference, which is exacerbated by the limited number of channels available, can severely degrade the performance of WLANs if an effective channel assignment scheme is not employed. In an earlier...
IEEE802.11DCF, which is a most widely used wireless LAN employs RTS/CTS handshake as an option for mitigating effects of hidden terminals. This handshake can prevent packet collisions by exchange RTS and CTS among transmitter and receiver in order to notify length of its transmission period to neighboring terminals. However, by the handshaking, terminals overhearing RTS and/or CTS prohibit its transmission...
In this paper we propose a new approach to designing a large scale wireless sensor network (WSN) with a cluster-tree topology. Sensors in each cluster communicate directly with their associated cluster head (CH) through contention-based transmissions, and communications between CHs use contention free transmissions. The objective is to balance the energy consumptions of all the CHs, while providing...
The active queue management in Internet routers exploits the idea that an incoming packet can be dropped by the router even if there is some available buffering space in the router. Therefore, the router can send congestion signals to TCP before the actual congestion occurs, preventing queues and delays from growing too high. Many active queue management algorithms has been proposed till now. Unfortunately,...
As a new type of wireless network architecture, because of its self-organization, and support multi-hop and heterogeneous networks, Wireless Mesh networks has played an important role in building ldquowireless citiesrdquo and become an research spot in academia and industry. In practical applications, network capacity is the most important need and high network throughput is the most important network...
We propose a short overview of models and results based on spatial models used to evaluate the performance of ad hoc networks. Locations of nodes are distributed in a two dimensional area according to a stochastic point process, which allows us to obtain the averages and distributions of different performance quantities. It is particularly suited in the context of ad hoc networks as the topology has...
TFRC protocol has not been designed to enable reliability. Indeed, the birth of TFRC results from the need of a congestion controlled and realtime transport protocol in order to carry multimedia traffic. Historically, and following the anarchical deployment of congestion control mechanisms implemented on top of UDP protocol, the IETF decided to standardize such protocol in order to provide to multimedia...
This paper investigates the use of the polarization as a diversity technique to allow the joint operation of co-located CDMA networks. We propose a closed-form expression for the link probability of success with respect to the topology of the deployment and the channel characteristics (code orthogonality and degree of polarization). Next, we derive the equivalence between the degree of polarization...
The ease of deployment and the self configurable aspect of wireless mesh networks has generated lot of interest in them during the recent years. The one laptop per child (OLPC) project uses mesh networking, closely adhering to IEEE 802.11s WLAN mesh standard, to provide networking in a classroom environment. Our work measures and analyzes the performance of OLPC mesh networks. It includes several...
We provide a simple and accurate analytical model for multi-cell IEEE 802.11 WLANs. Our model applies if the cell radius, R, is much smaller than the carrier sensing range, Rcs. We argue that, the condition Rcs >> R is likely to hold in a dense deployment of access points (APs). We develop a scalable cell level model for such WLANs with saturated nodes as well as for TCP-controlled long file...
We have currently reached a phase where big shifts in the network traffic might impose to rethink the design of current architectures, and where new technologies, being pushed into market, will act as enabler of such changes. Taking into account the current scenario and its likely evolution as well, in this paper we examine the case for multi-path routing within the metropolitan access network. Through...
Energy consumption is of utmost importance in wireless mesh networks where nodes are battery operated and have limited power resources. In this paper, we develop an analytical model to estimate the throughput-capacity of a wireless mesh network and use this model to study the network's bit-per-joule performance. We assume that each node uses an IEEE 802.11 based software controlled radio whose modulation/coding...
In this paper, we first propose a traffic model based on scale-free network to investigate the connections between the topology of a network and the routing strategies work on it. Then, we put forward a topology function with a tunable exponential parameter to represent the static part of local routing strategies. In order to make routing algorithms still work well even when the network falls into...
This paper introduces a novel mobility-aware routing protocol (MARP) for mobile, cognitive ad-hoc networks. Traditional routing protocols trigger the routing updates after the nodes detect the route failure. Even if the link condition is getting worse which means the link is likely to break in the future, the nodes will still transmit the packets along the current path. MARP uses cognitive techniques...
Multi-radio wireless mesh networks (WMN) is a feasible choice for several applications, as routers with multiple network interface cards (NICs) have become cheaper. Placement of multiple NICs on each router can significantly improve the network performance if channels are assigned wisely. This is due to the fact, that by using multiple non-interfering channels wireless interference is diminished....
In this paper, we present our design and implementation of load-balanced gateway discovery routing protocol called LBGD-AODV. A gateway node in a wireless mesh network acts as bridge between mesh routers and external network in order to provide services such as broadband. We observed in our SwanMesh testbed that a single gateway can only serve up to a limited number of hops due to noticeable throughput...
In this paper we examine the behavior of ad hoc networks through simulations, using different routing protocols and various topologies. We examine the difference in performance, using a CBR application, with packets of different size through a variety of topologies, showing that the way nodes are placed in a network has an impact in networks performance. We show that the choice of routing protocol...
Underwater acoustic networks (UAN) are becoming an integral part of a wide range of applications, such as those used for exploration and maintenance in the offshore oil and gas industry, surveillance for homeland security, subsea mine counter measures, marine environmental assessment and diving activities. For UAN, efficient and effective media access control (MAC) is a very important requirement...
The network-on-chip (NoC) has been recognized as a paradigm to solve system-on-chip (SoC) design challenges. The routing algorithm is one of key researches of a NoC design. XY routing algorithm, which is a kind of distributed deterministic routing algorithms, is simple to be implemented. Odd-even (OE) routing algorithm, whose implementation is complex, is a sort of distributed adaptive routing algorithms...
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