waashk/dblp huggingface dataset:
rdcf: a relay-enabled medium access control protocol for wireless ad hoc networks. it is well known that ieee 802.11 provides a physical layer multirate capability and, hence, mac layer mechanisms are needed to exploit this capability. several solutions have been proposed to achieve this goal. however, these solutions only consider how to exploit good channel quality for the direct link between the sender and the receiver. since ieee 802.11 supports multiple transmission rates in response to different channel conditions, data packets may be delivered faster through a relay node than through the direct link if the direct link has low quality and low rate. in this paper, we propose a novel mac layer relay-enabled distributed coordination function (dcf) protocol, called rdcf, to further exploit the physical layer multirate capability. we design a protocol to assist the sender, the relay node, and the receiver to reach an agreement on which data rate to use and whether to transmit the data through a relay node. considering various issues, such as, bandwidth utilization, channel errors, and security, we propose techniques to further improve the performance of rdcf. simulation results show that rdcf can significantly reduce the packet delay, improve the system throughput, and alleviate the impact of channel errors on fairness.
a five-phase reervation protocol (fprp) for mobile ad hoc networks. a new single channel, time division multiple access (tdma)-based broadcast scheduling protocol, termed the five-phase reservation protocol (fprp), is presented for mobile ad hoc networks. the protocol jointly and simultaneously performs the tasks of channel access and node broadcast scheduling. the protocol allows nodes to make reservations within tdma broadcast schedules. it employs a contention-based mechanism with which nodes compete with each other to acquire tdma slots. the fprp is free of the "hidden terminal" problem, and is designed such that reservations can be made quickly and efficiently with negligible probability of conflict. it is fully-distributed and parallel (a reservation is made through a localized conversation between nodes in a 2-hop neighborhood), and is thus scalable. a "multihop aloha" policy is developed to support the fprp. this policy uses a multihop, pseudo-bayesian algorithm to calculate contention probabilities and enable faster convergence of the reservation procedure. the performance of the protocol, measured in terms of scheduling quality, scheduling overhead and robustness in the presence of nodal mobility, has been studied via simulations. the results showed that the protocol works very well in all three aspects. some future work and applications are also discussed.
using statistical bandwidth in token ring networks. a new network access protocol, called restricted destination access protocol, for transmitting data packets in token ring networks, is proposed and analyzed. this protocol is based on the existing token passing access protocol and makes use of the extra statistical bandwidth that exists in token ring networks. a transmission capacity of greater than unity can be supported. simulation results using the protocol in a modified fiber distributed data interface (fddi) network are included
a source-based algorithm for delay-constrained minimum-cost multicasting. a new heuristic algorithm is presented for constructing minimum-cost multicast trees with delay constraints. the new algorithm can set variable delay bounds on destinations and handles two variants of the network cost optimization goal: one minimizing the total cost (total bandwidth utilization) of the tree, and another minimizing the maximal link cost (the most congested link). instead of the single-pass tree construction approach used in most previous heuristics, the new algorithm is based on a feasible search optimization method which starts with the minimum-delay tree and monotonically decreases the cost by iterative improvement of the delay-bounded tree. the optimality of the costs of the delay-bounded trees obtained with the new algorithm is analyzed by simulation. depending on how tight the delay bounds are, the costs of the multicast trees obtained with the new algorithm are shown to be very close to the costs of the trees obtained by the kou, markowsky and berman's algorithm (1981).
customized service creation: a new order for telecommunication services. the evolution from the intelligent network to the advanced intelligent network (ain) is described. the concept behind ain and its architecture are introduced. a bellcore product for the ain, the space system, is illustrated. the authors discuss the user-friendly programming language, service creation platform, multiple-services application, and reliable node platform of the space system
mobile radio slotted aloha with capture and diversity. in this paper, the slotted aloha protocol in a mobile radio environment, in the presence of ricean fading, two-fold antenna diversity and multiple reception capability, is considered. the capture probabilities and the average throughput are computed, and the issue of stability is addressed. it is shown that diversity can improve the system performance, although only to a certain extent. some extensions are also considered: in particular, the use of a higher degree of diversity is investigated.
fairness in broadband isdn. the authors propose a fairness criterion for sharing spare (unallocated) capacity among different nonguaranteed bursty data sources with different relative usage values. based on this criterion, the throughput of some sources may be controlled in the case where the total average offered traffic within a certain small time interval is greater than the total available spare capacity. it is proposed that all controlled sources will enjoy a share of capacity which is proportional to their relative usage values, and that no uncontrolled source will enjoy higher relative throughput than a controlled source. this criterion uniquely defines a set of throughputs for all sources. a method to compute these throughput values which has been demonstrated by several examples has been presented
a traffic engineering approach for placement and selection of network services. network services are provided by means of dedicated service gateways, through which traffic flows are directed. existing work on service gateway placement has been primarily focused on minimizing the length of the routes through these gateways. only limited attention has been paid to the effect these routes have on overall network performance. we propose a novel approach for the service placement problem, which takes into account traffic engineering considerations. rather than trying to minimize the length of the traffic flow routes, we take advantage of these routes in order to enhance the overall network performance. we divide the problem into two subproblems: finding the best location for each service gateway, and selecting the best service gateway for each flow. we propose efficient algorithms for both problems and study their performance. our main contribution is showing that placement and selection of network services can be used as effective tools for traffic engineering.
cr switch: a load-balanced switch with contention and reservation. load-balanced switches have received a great deal of attention recently as they are much more scalable than other existing switch architectures in the literature. however, as there exist multiple paths for flows of packets to traverse through load-balanced switches, packets in such switches may be delivered out of order. in this paper, we propose a new switch architecture, called the contention and reservation (cr) switch, that not only delivers packets in order but also guarantees 100% throughput. the key idea, as in a multiple-access channel, is to operate the cr switch in two modes: 1) the contention mode in light traffic and 2) the reservation mode in heavy traffic. to do this, we invent a new buffer management scheme, called virtual output queue with insertion (i-voq).with the i-voq scheme, we give rigorous mathematical proofs for 100% throughput and in-order packet delivery of the cr switch. by computer simulations, we also demonstrate that the average packet delay of the cr switch is considerably lower than other schemes in the literature, including the uniform frame spreading scheme [10], the padded frame scheme [8], and the mailbox switch [5].
optimal rate-reliability-delay tradeoff in networks with composite links. networks need to accommodate diverse applications with different quality-of-service (qos) requirements. new ideas at the physical layer are being developed for this purpose, such as diversity embedded coding, which is a technique that combines high rates with high reliability. we address the problem of how to fully utilize different rate-reliability characteristics at the physical layer to support different types of traffic over a network and to jointly maximize their utilities. we set up a new framework based on utility maximization for networks with composite links, meaning that each link consists of sub-links that can attain different rate-reliability characteristics simultaneously. we incorporate delay, in addition to rate and reliability, into the utility functions. to accommodate different types of traffic, we propose distributed algorithms converging to the optimal rate-reliability-delay tradeoff based on capacity division and priority queueing. numerical results show that compared with traditional codes, the new codes can provide higher network utilities for all traffic types simultaneously. the results also show that priority queueing achieves higher network utility than capacity division.
performance of random access scheduling schemes in multi-hop wireless networks. the scheduling problem in multi-hop wireless networks has been extensively investigated. although throughput optimal scheduling solutions have been developed in the literature, they are unsuitable for multi-hop wireless systems because they are usually centralized and have very high complexity. in this paper, we develop a random-access based scheduling scheme that utilizes local information. the important features of this scheme include constant-time complexity, distributed operations, and a provable performance guarantee. analytical results show that it guarantees a larger fraction of the optimal throughput performance than the state-of-the-art. through simulations with both single-hop and multi-hop traffics, we observe that the scheme provides high throughput, close to that of a well-known highly efficient centralized greedy solution called the greedy maximal scheduler.
load balancing in large-scale rfid systems. a radio frequency identifier (rfid) system consists of inexpensive, uniquely-identifiable tags that are mounted on physical objects, and readers that track these tags (and hence these physical objects) through rf communication. for many performance measures in large-scale rfid systems, the set of tags to be monitored needs to be properly balanced among all readers. in this paper we, therefore, address this load balancing problem for readers - how should a given set of tags be assigned to readers such that the cost for monitoring tags across the different readers is balanced, while guaranteeing that each tag is monitored by at least one reader. we first present centralized solutions to two different variants of this load balancing problem: (i) min-max cost assignment (mca), and (ii) min-max tag count assignment (mta). we show that mca, the generalized variant of the load balancing problem, is np-hard and hence present a 2-approximation algorithm for it. we next present an optimal centralized solution for mta, an important specialized variant of the problem. subsequently, we present a localized distributed algorithm that is probabilistic in nature and closely matches the performance of the centralized algorithms. finally we present detailed simulation results that illustrate the performance of the localized distributed approach, how it compares with the centralized optimal and near-optimal solutions, and how it adapts the solution with changes in tag distribution and reader topology. our results demonstrate that our schemes achieve very good performance even in highly dynamic large-scale rfid systems.
multicast scheduling in cellular data networks. multicast is an efficient means of transmitting the same content to multiple receivers while minimizing network resource usage. applications that can benefit from multicast such as multimedia streaming and download, are now being deployed over 3g wireless data networks. existing multicast schemes transmit data at a fixed rate that can accommodate the farthest located users in a cell. however, users belonging to the same multicast group can have widely different channel conditions. thus existing schemes are too conservative by limiting the throughput of users close to the base station. we propose two proportional fair multicast scheduling algorithms that can adapt to dynamic channel states in cellular data networks that use time division multiplexing: inter-group proportional fairness (ipf) and multicast proportional fairness (mpf). these scheduling algorithms take into account (1) reported data rate requests from users which dynamically change to match their link states to the base station, and (2) the average received throughput of each user inside its cell. this information is used by the base station to select an appropriate data rate for each group. we prove that ipf and mpf achieve proportional fairness among groups and among all users inside a cell respectively. through extensive packet-level simulations, we demonstrate that these algorithms achieve good balance between throughput and fairness among users and groups.
designing multihop wireless backhaul networks with delay guarantees. as wireless access technologies improve in data rates, the problem focus is shifting towards providing adequate backhaul from the wireless access points to the internet. existing wired backhaul technologies such as copper wires running at dsl, t1, or t3 speeds can be expensive to install or lease, and are becoming a performance bottleneck as wireless access speeds increase. longhaul, non-line-of-sight wireless technologies such as wimax (802.16) hold the promise of enabling a high speed wireless backhaul as a cost-effective alternative. however, the biggest challenge in building a wireless backhaul is achieving guaranteed performance (throughput and delay) that is typically provided by a wired backhaul. this paper explores the problem of efficiently designing a multihop wireless backhaul to connect multiple wireless access points to a wired gateway. in particular, we provide a generalized link activation framework for scheduling packets over this wireless backhaul, such that any existing wireline scheduling policy can be implemented locally at each node of the wireless backhaul. we also present techniques for determining good interference-free routes within our scheduling framework, given the link rates and cross-link interference information. when a multihop wireline scheduler with worst case delay bounds (such as wfq or coordinated edf) is implemented over the wireless backhaul, we show that our scheduling and routing framework guarantees approximately twice the delay of the corresponding wireline topology. finally, we present simulation results to demonstrate the low delays achieved using our framework.
jetmax: scalable max-min congestion control for high-speed heterogeneous networks. recent surge of interest towards congestion control that relies on single-link feedback (e.g., xcp, rcp, maxnet, emkc, vcp), suggests that such systems may offer certain benefits over traditional models of additive packet loss. besides topology-independent stability and faster convergence to efficiency/fairness, it was recently shown that any stable single-link system with a symmetric jacobian tolerates arbitrary fixed, as well as time-varying, feedback delays. although delay-independence is an appealing characteristic, the emkc system developed in exhibits undesirable equilibrium properties and slow convergence behavior. to overcome these drawbacks, we propose a new method called jetmax and show that it admits a low-overhead implementation inside routers (three additions per packet), overshoot-free transient and steady state, tunable link utilization, and delay-insensitive flow dynamics. the proposed framework also provides capacity-independent convergence time, where fairness and utilization are reached in the same number of rtt steps for a link of any bandwidth. given a 1mb/s, 10gb/s, or googol (10^1^0^0) bps link, the method converges to within 1% of the stationary state in six rtts. we finish the paper by comparing jetmax's performance to that of existing methods in ns2 simulations and discussing its linux implementation.
modeling per-flow throughput and capturing starvation in csma multi-hop wireless networks. multi-hop wireless networks employing random access protocols have been shown to incur large discrepancies in the throughputs achieved by the flows sharing the network. indeed, flow throughputs can span orders of magnitude from near starvation to many times greater than the mean. in this paper, we address the foundations of this disparity. we show that the fundamental cause is not merely differences in the number of contending neighbors, but a generic coordination problem of csma-based random access in a multi-hop environment. we develop a new analytical model that incorporates this lack of coordination, identifies dominating and starving flows and accurately predicts per-flow throughput in a large-scale network.we then propose metrics that quantify throughput imbalances due to the mac protocol operation. our model and metrics provide a deeper understanding of the behavior of csma protocols in arbitrary topologies and can aid the design of effective protocol solutions to the starvation problem.
low-complexity distributed scheduling algorithms for wireless networks. we consider the problem of designing distributed scheduling algorithms for wireless networks. we present two algorithms, both of which achieve throughput arbitrarily close to that of maximal schedules, but whose complexity is low due to the fact that they do not necessarily attempt to find maximal schedules. the first algorithm requires each link to collect local queue-length information in its neighborhood, and its complexity is otherwise independent of the size and topology of the network. the second algorithm, presented for the node-exclusive interference model, does not require nodes to collect queue-length information even in their local neighborhoods, and its complexity depends only on the maximum node degree in the network.
fault-tolerant relay node placement in heterogeneous wireless sensor networks. existing work on placing additional relay nodes in wireless sensor networks to improve network connectivity typically assumes homogeneous wireless sensor nodes with an identical transmission radius. in contrast, this paper addresses the problem of deploying relay nodes to provide fault tolerance with higher network connectivity in heterogeneous wireless sensor networks, where sensor nodes possess different transmission radii. depending on the level of desired fault tolerance, such problems can be categorized as: 1) full fault-tolerant relay node placement, which aims to deploy a minimum number of relay nodes to establish k (k \ge 1) vertex-disjoint paths between every pair of sensor and/or relay nodes and 2) partial fault-tolerant relay node placement, which aims to deploy a minimum number of relay nodes to establish k (k \ge 1) vertex-disjoint paths only between every pair of sensor nodes. due to the different transmission radii of sensor nodes, these problems are further complicated by the existence of two different kinds of communication paths in heterogeneous wireless sensor networks, namely, two-way paths, along which wireless communications exist in both directions; and one-way paths, along which wireless communications exist in only one direction. assuming that sensor nodes have different transmission radii, while relay nodes use the same transmission radius, this paper comprehensively analyzes the range of problems introduced by the different levels of fault tolerance (full or partial) coupled with the different types of path (one-way or two-way). since each of these problems is np-hard, we develop o(\sigma k^2)-approximation algorithms for both one-way and two-way partial fault-tolerant relay node placement, as well as o(\sigma k^3)-approximation algorithms for both one-way and two-way full fault-tolerant relay node placement (\sigma is the best performance ratio of existing approximation algorithms for finding a minimum k-vertex connected spanning graph). to facilitate the applications in higher dimensions, we also extend these algorithms and derive their performance ratios in d-dimensional heterogeneous wireless sensor networks (d \ge 3). finally, heuristic implementations of these algorithms are evaluated via qualnet simulations.
prime: peer-to-peer receiver-driven mesh-based streaming. the success of file swarming mechanisms such as bittorrent has motivated a new approach for scalable streaming of live content that we call mesh-based peer-to-peer (p2p) streaming. in this approach, participating end-systems (or peers) form a randomly connected mesh and incorporate swarming content delivery to stream live content. despite the growing popularity of this approach, neither the fundamental design tradeoffs nor the basic performance bottlenecks in mesh-based p2p streaming are well understood. in this paper, we follow a performance-driven approach to design prime, a scalable mesh-based p2p streaming mechanism for live content. the main design goal of prime is to minimize two performance bottlenecks, namely bandwidth bottleneck and content bottleneck. we show that the global pattern of delivery for each segment of live content should consist of a diffusion phase which is followed by a swarming phase. this leads to effective utilization of available resources to accommodate scalability and also minimizes content bottleneck. using packet level simulations, we carefully examine the impact of overlay connectivity, packet scheduling scheme at individual peers and source behavior on the overall performance of the system. our results reveal fundamental design tradeoffs of mesh-based p2p streaming for live content.
optimal pricing in a free market wireless network. we consider an ad-hoc wireless network operating within a free market economic model. users send data over a choice of paths, and scheduling and routing decisions are updated dynamically based on time varying channel conditions, user mobility, and current network prices charged by intermediate nodes. each node sets its own price for relaying services, with the goal of earning revenue that exceeds its time average reception and transmission expenses. we first develop a greedy pricing strategy that maximizes social welfare while ensuring all participants make non-negative profit. we then construct a (non-greedy) policy that balances profits more evenly by optimizing a profit fairness metric. both algorithms operate in a distributed manner and do not require knowledge of traffic rates or channel statistics. this work demonstrates that individuals can benefit from carrying wireless devices even if they are not interested in their own personal communication.