建设多媒体通信网 加速国家信息化

邮电公网是国家信息基础设施的网络基础，而建设公众多媒体通信网是对这个网络基础的进一步完善和提高。必须充分发挥邮电固有的网络优势，尽快建成多功能的多媒体通信网，切实推动国家信息化进程。本文透彻地论述了通信在国家信息化中的地位和作用以及多媒体通信在整个通信发展和国家国民经济信息化中的地位和作用，并对在发展多媒体通信中应处理好的几个问题和加以论述。     

试论公用通信网和专用通信网的合作

就我国公用通信网和专用通信网合作的必然性、原则和精神、方式及影响合作的不利因素作了论述     

江苏省专用通信网与公用网的联网

江苏省专用通信网与公用网的联网王云飞，孙克兰１江苏省专用通信网现状江苏省专用通信网大部分分布于南京和徐州地区。从建网方式看可分为以下３种类型。第一种类型是自行建设长途通信线路，自备交换机和终端设备组成自己的专用通信网。这类专用网具有较强的封闭性，有经...     

卫星通信网络应用软件的设计与实现

本文主要介绍我们研制开发的卫星网络应用软件的总体设计方法，有关模块功能的实现及其相尖的操作说明。该软件可用于军、民用通信卫星的网络管理、辅助决策和系统设计。     

TD-SCDMA网络2/3G共LAC区及精确LAC区边界划分

在现阶段TD-SCDMA网络与GSM网络共同组网的情况下,2/3G互操作作为两代网络互惠互补的有效手段得到了广泛应用和发展。要提升网络指标和用户感知,需要提高2/3G互操作成功率、缩短2/3G互操作时延。目前很多地市开展网络优化的过程中已开始进行缩短2/3G互操作时延的尝试,2/3G共LAC区便是其中较为成功的一例。在此基础上,进行精确LAC区边界划分的专项优化,可以在2/3G共LAC区的效果之下,达到进一步提升和完善网络性能的效果。     

Performance of amplify forward and decode forward cooperative strategies for body surface communications in UWB Body Area Networks

Body area networks (BAN) are being developed for telemonitoring of patients. Ultra wideband (UWB) is the most preferred choice for the physical layer of the BAN as it provides high data rate at low power consumption along with a simple transceiver structure. But because of high fading characteristics of the human body channel, the range of UWB will be limited, and a reliable communication cannot be guaranteed. In that case, cooperative communications may be applied to BAN for improving system performance and link quality. The paper proposes a novel approach by applying amplify and forward, and decode and forward cooperative relaying strategies with maximal ratio combining for BAN. The performance of single relay AF and DF relaying have been compared with direct transmission. Further, the efficacy of the proposed strategies has been validated by transmitting electrocardiogram signals and magnetic resonance imaging images. Simulations and validations have been carried out on Institute of Electrical and Electronics Engineers designated CM3 channel model for BAN designed from real time measurements data. A signal‐to‐noise ratio gain of at least 3 dB is clearly observed from simulation results. Thus, transmit power requirement can be minimized, which in turn improves the battery life of body sensor nodes. Copyright © 2015 John Wiley & Sons, Ltd.