Mobility Management in Next Generation Wireless Systems

未来的无线移动系统承诺覆盖全球，并要求终端能够在不同类型的网络之间无缝漫游。下一代移动终端将必须存在于一个多种标准的世界中，移动性管理程序（即位置注册、寻呼和切换）必须在网络提供商和网络骨干以及地理区域之间互操作。将研究位置注册、寻呼和切换，并引入新的协议来解决这些问题。从位置管理的角度来看，移动终端在进入新系统之前必须进行注册，以便预留无线电资源。此外，还需要对信令格式进行转换，对移动终端进行认证。提出了一种估算用户移动性模式的新方案，以帮助新协议的开发，并估算新的移动性管理过程的信令成本。此外，还提出了一种新的系统间位置更新方案，该方案通过分配基于每个用户配置文件的更新距离阈值来减少信令流量。此外，引入了边界位置区域，使mt能够请求两个不同系统之间的位置更新。未来无线系统的另一个问题是系统间分页问题。所述搜索操作不仅可以在移动终端最后一次注册的系统中进行，而且可以在移动终端最后一次呼叫后经过的系统中进行。提出了一种新的方案，将寻呼区域按位置概率降序进行组合和重新排序，直到延迟界达到一定的阈值作为QoS参数。对于切换管理，无线接入系统必须支持具有多个连接的移动终端的系统间切换，这些移动终端发送和接收具有不同QoS （Quality of Service）期望的多媒体流量。无线电信号强度必须在不同的空中接口和功率水平上进行测量和比较，信令程序必须在每个系统的交换机之间协作。提出了一种新的系统间切换方案，在移动终端开始切换到新系统时，利用边界单元进行系统转换。最后，开发一种新的信令协议，将移动终端切换到边界小区，进行格式转换，然后将移动终端切换到新系统。

Future wireless mobile systems promise universal coverage and require terminals to be capable of seamless roaming between networks, which may be of different types. Next generation mobile terminals will haveto exist in a world of multiple standards, and mobility management procedures (i.e., location registration, paging and handoff) will have to be interoperable across network providers and network backbones as well as geographical regions. Location registration, paging and handoff will be investigated, and new protocols will be introduced to solve these problems. From the standpoint of location management, the mobile terminals must register before they enter new systems in order to reserve radio resources. In addition, the signaling formats must be converted and the mobile terminals must be authenticated. A new scheme is proposed, which estimates the user mobility pattern in order to help new protocols and to estimate the signaling costs of the new mobility management procedures. Also, a new intersystem location update scheme is introduced, which reduces the signaling traffic by assigning update distance thresholds based on a per-user profile. Furthermore, the boundary location area is introduced, which enables the MTs to request location update between two different systems. Another problem for future wireless systems is the intersystem paging problem. The search operation may be carried out not only in the system where the mobile terminal last registered, but also in the system the mobile terminal has passed since the last call. A new scheme is proposed that combines and reorders the paging areas in decreasing order of location probabilities, until the delay bound has reached a certain threshold value as a QoS parameter. For handoff management, the radio access system must support intersystem handoffs for mobile terminals with multiple connections that are sending and receiving multimedia traffic with different Quality of Service (QoS) expectations. Radio signal strengths must be measured and compared across different air interfaces and power levels, and signaling procedures must cooperate between the switches of each system. A new intersystem handoff scheme is proposed that uses boundary cells to perform system transformations when mobile terminals begin to handoff into new systems. Finally, a new signaling protocol will be developed to handoff the mobile terminal into the boundary cell, perform the format transformation, and then handoff the mobile terminal into the new system.