1. Field
The present invention relates generally to communication, and more specifically to techniques for downloading and displaying system tags in wireless communication systems.
2. Background
Wireless communication systems are widely deployed to provide various communication services such as voice, packet data, and short messages. These systems may be multiple-access systems capable of supporting communication with multiple users by sharing the available system resources. Examples of such multiple-access systems include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, and frequency division multiple access (FDMA) systems. A CDMA system may be designed to implement one or more standards such as IS-2000, IS-95, W-CDMA, and so on. A TDMA system may be designed to implement one or more standards such as Global System for Mobile Communications (GSM).
A network operator/service provider may deploy one or more wireless communication systems to provide services for its subscribers. Each deployed system covers a particular geographic region (e.g., a city) and may in turn include one or more smaller networks. For CDMA, each system can be uniquely identified by a specific system identification (SID) code value, and each network may also be uniquely identified by a specific network identification (NID) code value. Each base station operated by the network operator would then transmit the SID and NID values of the specific system and network to which it belongs.
Wireless terminals operated by the subscribers are typically located throughout the coverage areas of the deployed systems. For CDMA, a terminal may include a preferred roaming list (PRL) that identifies the specific systems that the terminal can access and (optionally) the systems that the terminal cannot access. The terminal further maintains a list of one or more home systems, with each home system being identified by its unique (SID, NID) pair. The terminal can then determine whether or not it is in communication with a home system based on its home (SID, NID) pairs and the (SID, NID) pair received from a serving system. The serving system is the system from which the terminal obtains service. The terminal is deemed to be roaming if the (SID, NID) pair received from the serving system does not match any one of the home (SID, NID) pairs.
Conventionally, for CDMA, a wireless terminal has means to display a roaming indicator (which is typically an icon) and/or specific text strings based on its roaming status. For example, if the terminal is obtaining service from a home system, then it may display the name of the home service provider on a terminal screen. Conversely, if the terminal is obtaining service from a roaming system (i.e., a system that is not a home system), then it may indicate its roaming condition in accordance with a roaming indicator value associated with the roaming system. This roaming indicator value may be stored in a system record maintained for the roaming system and included in the preferred roaming list. Conventionally, the type of information that may be conveyed by the terminal for roaming is limited and specifically defined by TIA/EIA-683-B Annex C. For example, the roaming indicator value may direct the terminal to display the roaming indicator/icon and/or display a specific text string on the terminal screen.
CDMA systems have been widely deployed and international roaming has become more prevalent. Service providers may desire to provide different and/or more specific information to their subscribers based on roaming conditions. For example, a service provider may desire to provide the name of a roaming system to a terminal so that the system name can be displayed on the terminal screen for a subscriber.
There is therefore a need in the art for techniques to download and display information based on roaming status of the terminals.