Diversity reservation ALOHA

A multiaccess protocol suitable for packet satellite broadcast channels is introduced in this paper. The proposed protocol, called diversity reservation ALOHA (DRA) combines the essential features of announced retransmission random access (ARRA). diversity ALOHA, and a reservation scheme with a slotted ALOHA reservation channel to achieve the goals of improved delay-throughput characteristics and high channel utilization. Two versions of DRA protocols are analyzed. In scheme 1, called DRA with reservation cleared (DRA-RC), no global queue information is required for a user to access the channel. In this version, even a successful transmission of reservation requests will be cleared from the system if it causes overflow. The second scheme, called DRA with reservation delayed (DRA-RD), establishes a global queue distributed at users' terminals, so that users with successful transmission of reservation requests are assured of access rights although transmission may be delayed to later fames. Important system performance measures, such as activity-factor-throughput characteristics, for DRA-RC and DRA-RD are compared with those of ARRA. Examples of numerical results show that with system parameters properly chosen, substantial increases in attainable channel utilization are possible. Furthermore, the use of diversity for reservation allows a smaller packet delay especially under light traffic conditions. The analysis is validated in light of the simulation results.     

自助服务终端技术的专利分析

随着服务的不断丰富和发展,服务业已经成为现代经济增长的重要推动力量.近年来,随着人们对自助服务的强烈需求,一种便利且有效的服务形式——自助服务终端应运而生,各大企业和机构纷纷展开对该技术的专利部署.针对自助服务终端技术的发展现状、重要申请人的专利特点、专利发展趋势等进行详细的分析和研究,从而对目前中国自动服务终端的发展有进一步了解.     

基于单片机控制的自助实验室教学系统设计

文章介绍了利用单片机控制RA8806为控制器的LCD模块和利用单片机控制AU6850B为核心的MP3模块的自助实验室教学系统设计.本系统安装在每个实验台上,学生通过本系统触摸屏上触摸按钮,找出与之对应的实验仪器语音和文字教学文件,一对一为学生教学,提高课堂效率,节约教学成本.     

自助安全评估系统在入网验收工作中的运用实践

采用人工方式完成入网安全验收工单,一名高级技术人员平均每月最多能完成10张入网安全验收工单,由于业务上线原因,入网安全验收时限要求非常严格,手工方式已无法满足业务上线对入网安全验收高效率要求.自助安全评估系统的开发和在入网安全验收应用,从根本上解决了手工方式导致入网安全验收效率低下的问题.     

Minislotted packet reservation multiple access

A minislotted packet reservation multiple access (PRMA) protocol is proposed in response to the disadvantage of PRMA wherein an entire slot is wasted in the event of a collision. The proposed protocol is shown to yield improvements over PRMA at the expense of introducing small amounts of additional clipping in some talkspurts.<>     

Avaya提升联络中心个性化与自助服务水平

Avaya公司日前宣布推出联络中心解决方案套件Avaya Customer Interaction Suite,该套件融合多种全新的领先功能,能够通过各种通信渠道提供个性化客户服务,并提高自助服务的可扩展性。 新套件中的每一种解决方案,包括联络管理、自助服务、主动联络(pro-active contact)与有效运营(operational effectiveness),都支持Avaya联络中心的最新版应用。这些应用被整合到一个集成产品     

Fractional channel reservation in mobile communication systems

A fractional channel reservation scheme is proposed. In conventional channel reservation schemes, the number of channels reserved for handoff calls has always been an integer. The proposed fractional channel reservation algorithm can be used to finely control the communication service quality. By varying the number of reserved channels for handoff calls by fractions of one     

A model of reservation systems

The author considers the performance evaluation of an advanced capacity reservation system using the CCITT defined reserved call establishment mode. A simple model for the traffic process is introduced: calls are assumed to be offered uniformly to the reservation book. The state of the system can then be described statistically in terms of the population of various types of islands of free time slots. The limit where the length of the reservation book tends to infinity is, in particular, considered. For single-server systems with a deterministic holding time of one or two time slots, a closed-form solution is found. For a general holding time distribution, an asymptotic analytical solution is derived and corrections to this asymptotic solution are calculated numerically. For multiserver systems with geometric holding time distribution, the author presents numerical results obtained by simulations. An interpolation formula valid for all traffic intensities is developed. A procedure is given to extrapolate the results to larger systems than were actually simulated     

Contention free inter-cellular slot reservation

A distributed reservation protocol tailored for cellular wireless networks is presented that facilitates contention free inter-cellular slot allocation and reservation. While reserved slots are protected from inter-cell interference by a busy burst enabled reservation protocol, collisions due to simultaneously accessed unreserved slots by neighboring cells are mitigated by means of resource partitioning patterns. Shifting these partitioning patterns over time allows each cell to successively probe all slots. This ensures that full frequency reuse is maintained, in the way that all cells may utilize the entire frequency band. In effect a contention free inter-cellular slot allocation policy is established that in a distributed manner dynamically controls the spatial reuse, in terms of concurrently accessed radio resources by neighboring cells.     

Relaxed resource advance reservation policy in grid computing

The advance reservation technique has been widely applied in many grid systems to provide end-to-end quality of service (QoS). However, it will result in low resource utilization rate and high rejection rate when the reservation rate is high. To mitigate these negative effects brought about by advance reservation, a relaxed advance reservation policy is proposed, which allows accepting new reservation requests that overlap the existing reservations under certain conditions. Both the benefits and the risks of the proposed policy are presented theoretically. The experimental results show that the policy can achieve a higher resource utilization rate and lower rejection rate compared to the conventional reservation policy and backfilling technique. In addition, the policy shows better adaptation when the grid systems are in the presence of a high reservation rate.     

金融交易网络中自助设备交易质量测量方法

针对金融交易网络可靠性、实时性和安全性的网络通信要求,采用流量镜像和探针采集方式,利用深度包检测技术识别自助设备交易业务流量,从交易场景分析测量自助设备交易业务层面性能指标,结合网络性能参数对自助设备交易业务交易质量进行综合分析,为自助设备交易业务性能优化提供决策依据。     

触摸屏自助点菜终端的设计与实现

设计并实现了一种自助点菜终端,采用8寸液晶触摸屏作为人机交互界面,提供图文并茂的电子菜单。针对嵌入式系统存储空间的局限性,提出一种应用层软件与底层软件分离的存储运行方式,解决了大容量数据的存储与更新问题。采用开放源代码的图形用户接口软件Nano—X窗口系统,详细探讨了其配置与移植的方法。系统具有交互界面良好,易于生产维护的特点。     

基于无线通信技术的图书馆自助服务研究

无线通信技术应用于图书馆领域后,使数字图书馆自助服务的开放性、自主性得到空前的拓展.文章在介绍无线通信技术的基础上,阐述了以无线通信为技术支撑的图书馆馆内、馆外两种自助服务模式,给出了两种自助服务的无线应用终端与数字图书馆的链接关系.     

Point-to-point blocking probability in switching networks with reservation

In this paper reservation algorithms for multi-service switching networks are proposed. Two new approximate methods of the point-to-point blocking probability calculation in the multi-service switching networks are also presented in the paper. These methods can be used for blocking calculation in the switching networks with and without reservation. Special attention is paid to the method for determining the effective availability, which directly affects the accuracy of the final results. The results of analytical calculations are compared with the data of digital simulation of switching networks without and with reservation.     

网格环境中可靠性增强的资源预留策略

提出一种基于随机服务模型的可靠性量化计算方法,该策略采用随机服务系统描述网格资源的预留服务模型,通过分析预留请求的统计特征来评估接纳当前预留请求不发生违约的概率,然后依据备选资源集合中的违约概率来进行预留请求接纳和任务资源选择,从而提高资源预留时的可靠性。实验表明,与传统的预留策略相比,该策略在提高资源利用率、降低违约率以及对动态负载压力变化情况下的反应方面,表现出更好的有效性、适应性。     

南京市自助医疗服务系统方案设计

从医疗信息化实施的背景出发,对现有系统门诊患者就医时间长的实际问题加以分析,提出了系统建设原则、设计思路和实现方法,得出系统设计方案.通过建立自助服务系统,可以有效地解决现有系统所面临的各种问题,对推动医院的信息化建设具有实际意义.     

Resource reservation with pointer forwarding schemes for the mobileRSVP

We propose a pointer forwarding scheme for the mobile resource reservation protocol (MRSVP) to reduce the resource reservation cost on the wireless Internet. We show that the pointer forwarding scheme could significantly degrade the reservation cost when a mobile host performs locality movement     

城市无人值守噪音监测及信息发布系统

本文介绍了一种城市无人值守噪音监测及信息发布系统,它是由主控中心和分布在城市中的各监测站点组成,并讲述了该系统结构及工作原理.以及能够从计算机的显示附加装置获得模拟信号用作LED显示屏图象及文字显示所需的数据,实现与计算机屏幕同步显示.借助专用软件调整显示窗口的位置及大小,无须使用特殊的显示附件,因而比以前更灵活、更方便.无人值守工作站很容易实施,具有实用价值.     

Predictive mobile-oriented channel reservation schemes in wireless cellular networks

Provision of seamless service to multimedia applications in cellular wireless networks largely depends on the way calls are handled during handoff. Hence, sufficient resources must be provided for handoff (HO) connections when a mobile station (MS) moves from one cell to another. Effective allocation of resources can be achieved when the exact future trajectory of MSs is known in advance. However, such a scenario is unrealistic. The next best possibility is to employ user mobility prediction to determine the cell(s) a MS will likely visit in the near future. In this paper, we present an extensive survey and classification of channel (bandwidth) reservation schemes which employ user mobility prediction in the resource reservation process. We also present a survey and classification of call admission control (CAC) schemes, including discussion of prioritized and non-prioritized handoff schemes, which can be useful for researches both in academia and industry.