Bipartite communication networks with optimal connectivity

A network configuration is described which offers a maximal number of alternative paths between pairs of vertices for a given number of links. A trunking scheme for switched networks, based on this configuration, offers a better ratio of alternative paths to crosspoints than is given by simple link trunking.     

Class of optimal damage-resistant communication nets

It is shown that the product Kn×Kn of the complete graph Kn with itself is an optimal damage-resistant net in the Boesch and Thomas sense, i.e. Kn×Kn is optimally invulnerable to disconnection by either vertex or line removal.     

移动通信网络下通信最优节点自动选择方法研究

现有通信最优节点的选择方法,不能在保证误码率的前提下完成节点自动选择。为了解决上述问题,通过LTE网络架构、统一核心网络,从根本上降低因用户移动而造成数据分组丢失可能性,完成移动通信网络环境的搭建;应用通信误码率的计算与最优节点的自动选择,搭建基于移动网络的EBCPS通信最优节点自动选择方法。模拟应用环境设计对比实验结果表明,EBCPS通信最优节点自动选择方法,既能在保证误码率的前提下,完成节点自动选择,也能提高最小剩余量,缩短竞争接入时间。     

Joint problem of power optimal connectivity and coverage in wireless sensor networks

This work considers a multi-hop sensor network and addresses the problem of minimizing power consumption in each sensor node locally while ensuring two global (i.e., network wide) properties: (i) communication connectivity, and (ii) sensing coverage. A sensor node saves energy by suspending its sensing and communication activities according to a Markovian stochastic process. We show that a power level to induce a coverage radius is sufficient for connectivity provided that w(n)→∞. The paper presents a Markov model and its solution for steady state distributions to determine the operation of a single node. Given the steady state probabilities, we construct a non-linear optimization problem to minimize the power consumption. Simulation studies to examine the collective behavior of large number of sensor nodes produce results that are predicted by the analytical model.     

拥塞高速数据通信网优化控制模型

针对多信源——信宿高速数据通信网，引入N用户非零和微分对策优化控制路由模型。通信网中每个用户(决策者)，通过决策瞬时队列、路由及通信流量速率，使优化指标(损耗函数)达到最小；给出了反馈Nash平衡解的充要条件，并进行讨论。     

基于最优连通功率的无线传感器网络稳定成簇算法

针对节点实际部署中网络易割裂及热点区域节点密集、竞争激烈的情况,提出了一种基于最优连通功率的无线传感器网络稳定成簇算法.算法基于最优邻居节点数,利用可变功率调制技术,有效提高了网络的信道利用率和网络吞吐量,实现了分簇网络的稳定连通和稳定成簇,简化了网络拓扑结构,最大限度地延长了网络生命周期.实验仿真结果表明,算法有效维持了网络的连通性和稳定性,具有较强的自适应能力,在提升网络的整体性能上作用明显.     

大气光通信中应用最优选择分集

针对大气光通信中湍流对接收端误码率的影响,提出利用空间分集技术,通过对多发射器、多接收器最优选择来改善信噪比,降低误码率。仿真结果表明,当湍流较强时,多发射多接收比单发射单接收对系统的性能有更明显的改善。同时表明,在对数正态分布的光信道上,最优选择的效果与在瑞利衰落的无线信道上的效果基本相同。     

Set reconciliation with nearly optimal communication complexity

We consider the problem of efficiently reconciling two similar sets held by different hosts while minimizing the communication complexity, which we call the set reconciliation problem. We describe an approach to set reconciliation based on a polynomial encoding of sets. The resulting protocols exhibit tractable computational complexity and nearly optimal communication complexity when the sets being reconciled are sparse. Also, these protocols can be adapted to work over a broadcast channel, allowing many clients to reconcile with one host based on a single broadcast, even if each client is missing a different subset.     

Dual connectivity for LTE-advanced heterogeneous networks

Dual connectivity (DC) allows user equipments (UEs) to receive data simultaneously from different eNodeBs (eNBs) in order to boost the performance in a heterogeneous network with dedicated carrier deployment. Yet, how to efficiently operate with DC opens a number of research questions. In this paper we focus on the case where a macro and a small cell eNBs are inter-connected with traditional backhaul links characterized by certain latency, assuming independent radio resource management (RRM) functionalities residing in each eNB. In order to fully harvest the gain provided by DC, an efficient flow control of data between the involved macro and small cell eNBs is proposed. Moreover, guidelines for the main performance determining RRM algorithms such as UE cell association and packet scheduling are also presented. It is demonstrated how proper configuration of the proposed flow control algorithm offers efficient trade-offs between reducing the probability that one of the eNBs involved in the DC runs out of data and limiting the buffering time. Simulation results show that the performance of DC over traditional backhaul connections is close to that achievable with inter-site carrier aggregation (CA) and virtually zero-latency fronthaul connections, and in any case it is significantly higher compared to the case without DC.     

Class of Hamiltonian-partitionable networks

It is shown that, if the graph G of a network N is the sum of n Hamiltonian circuits, the product G×G of G with itself is the sum of 2n Hamiltonian circuits. For example, C×C, where C is a circuit, is the sum of two Hamiltonian circuits, and K2n+1×K2n+1, where K2n+1 is the complete graph of order 2n+1, is the sum of 2n such circuits.     

无线传感器网络覆盖连通性研究

针对无线传感器网络部署区域由于通信障碍和其他一些因素产生的某些节点无法与网络通信的情况,绐出了一种使用节点代理解决监测区域内节点通信不可达的方案,并基于一般意义的网络系统模型提出了一种探测覆盖区域内节点连通性的算法,即基于深度探测的节点覆盖连通性判定算法DBDAFNCJ.节点连通性分析和仿真实验结果表明,节点代理方案可以很好改善节点部署区域内节点通信不可达的情况,同时表明DBDAFNCJ算法可以高效、准确地获悉部署区域内节点连通性的情况.     

Lexicographically optimal balanced networks

We consider the problem of allocating bandwidth between two endpoints of a backbone network so that no parts of the network are unnecessarily loaded. We formulate the problem as lexicographic optimization and develop algorithms for its solution. The solution consists of: (1) identifying a cut in the network where the optimal load can be determined on all the links of the cut and (2) considering the same problem for each of the subnetworks to which the cut is dividing the original network.     

HDTV communication systems in broadband communication networks

Two high-definition television (HDTV) communication systems created for broadband communication networks are discussed. Nationwide HDTV transmission and distribution services and HDTV subscriber distribution services are examined. A network architecture for high-quality HDTV transmission is described. The transmission bit rates of HDTV services, which are the basic factors in constructing the network frame, are considered. Two HDTV coding algorithms, subband discrete cosine transform (DCT) and subband differential pulse-code modulation (DPCM) are described, and their coding bit rates discussed. A synchronous-digital-hierarchy-based synchronous transfer mode network design suitable for the transmission of HDTV signals in broadband communication networks are described     

Class of optimal recursive Wiener filters

Procedures are presented to generate a class of Wiener filters realisable through recursive filters. These filters possess the property that they minimise the spectral components of the error between the desired and output response.     

On the connectivity of wireless multi-hop networks with arbitrary wireless channel models

Considering a wireless multi-hop network where a total of n nodes are randomly, independently and uniformly distributed in a unit square in R² and each node has a uniform transmission power, a fundamental problem is to investigate the connectivity of such networks. In this letter, we prove that the probability of having a connected network and the probability of having no isolated node asymptotically converges to the same value as n goes to infinity for an arbitrary wireless channel model satisfying certain intuitively reasonable conditions.     

Asymptotically optimal cooperative wireless networks with reduced signaling complexity

This paper considers an orthogonal amplify-and-forward (OAF) protocol for cooperative relay communication over Rayleigh-fading channels in which the intermediate relays are permitted to linearly transform the received signal and where the source and relays transmit for equal time durations. The diversity-multiplexing gain (D-MG) tradeoff of the equivalent space-time channel associated to this protocol is determined and a cyclic-division-algebra-based D-MG optimal code constructed. The transmission or signaling alphabet of this code is the union of the QAM constellation and a rotated version of QAM. The size of this signaling alphabet is small in comparison with prior D-MG optimal constructions in the literature and is independent of the number of participating nodes in the network