一、试验地的选择(见上一章) 二、试验地的区划和标记 主要注意在进行试验地区化时要根据试验地面积、小区 大小、非试验条件差异状况、重复区、保护行等合理规划。 小区标记一般采用用罗马数字标明重复区(区组),下 角标处理代号,例如I2,Ⅳ等

当一项科研项目在完成田间试验、室内分析测定以及 对获得的数据要进行整理和统计分析等一系列工作之后, 要对科研工作进行必需的总结

一、SMS采用了哪两大机制,以保证短信息传输的可靠性? GSM系统的SMS技术包含两大机制:存储转发机制和传递确认机制。正是这两大机制保证了短信息传递的可靠性,也使得它与无线寻呼系统的文字寻呼相比显得更为优越

MIT OCW DATA COMMUNICATION CONTENTS Lectures 2 The Data Link Layer: Framing and Error Detection Lectures 3 4 The Data link layer: arQ Protocols Lectures 5 6 Introduction to Queueing Theory Lectures 8&9 M/G/I Queues

一、SIM卡应用工具 二、无线应用协议

一、主要承载技术GPRS 二、短消息业务

Outline Network Layer and Internetworking The TCP/IP protocol suit ATM

Flow control: end-to-end mechanism for regulating traffic between source and destination Congestion control: Mechanism used by the network to limit congestion The two are not really separable, and I will refer to both as flow control In either case, both amount to mechanisms for limiting the amount of traffic entering the network Sometimes the load is more than the network can handle Eytan Modiano

A packet switch consists of a routing engine(table look-up), a switch scheduler, and a switch fabric. The routing engine looks-up the packet address in a routing table and determines which output port to send the packet. Packet is tagged with port number The switch uses the tag to send the packet to the proper output port Eytan Modiano

Broadcast Routing Route a packet from a source to all nodes in the network Possible solutions: Flooding: Each node sends packet on all outgoing links Discard packets received a second time Spanning Tree Routing: Send packet along a tree that includes all of the nodes in the network