In the lower layer of local network, the protocol is Ethernet, which is based on bus topology and channel competition. So the most important problem for distributed parallel computing is too larger for communication spending. 基于网络环境的分布式并行计算中,通常局域网的底层通信协议多为以太网协议,而以太网采用的是总线通信和信道竞争两种技术,这样就存在通信冲突率提高、通信效率低下的问题。
DECT is an access technique that corresponds to the lower 3 layers of the OSI model, and has no agreement at physics construction and application layer in protocol, so a designer should design according to the customer's demand. DECT严格来说是一种接入技术,它对应于OSI的底三层,对于具体的物理结构和应用层方面没有在协议上作规定,所以设计者应该根据用户的需要作具体的设计。
Currently fault localization serves mainly to diagnose faults at the lower layer of the protocol stack. Fault diagnoses should be performed in an integrated way in new network environments. 目前故障定位的工作主要还是诊断协议栈中较低层的故障,新的网络环境需要故障诊断能够在协议栈的多层中综合完成。
Abstract description and program language and the support from lower layer protocol. 1抽象描述向具体开发语言的转化问题,低层通信协议支持问题分别提出了相应的解决策略。
Because it has higher efficiency and lower cost in encapsulation, PPP is chosen as a link layer protocol in POS to offer data encapsulation and link controling. 由于其具有封装效率高、开销低等优点,在POS技术中被用作提供数据封装和链路控制功能的数据链路层协议。
For the compatibility of the monitoring devices working in the lower layer, a general serial communication protocol and the serial communication scheduling module were designed. 为了众多底层监控设备串行通信的兼容,作者制定了一个通用串行通信协议,并设计了串行通信调度模块。
The software architecture of testing platform is consisting of physical layer software, driver, lower layer protocol software, high layer protocol software and user interface control software. 测试平台包含物理层软件、低层协议栈软件、高层协议栈软件及用户界面与主控软件四个部分。高层协议栈软件由TTCN-2协议测试部分与适配层软件部分组成。