## 1 Introduction  
One of the major issues in the future Internet is the integration of telecom networks with the Internet. In many countries, large _Internet Service Providers_ (ISPs) are also telecom operators; for example, Chunghwa Telecom operates HiNet, the largest ISP in Taiwan. These telecom operators have been focusing on providing Internet services through their telecom networks using telecom-grade mechanisms. In this article, we show that _IP Multimedia Subsystem_ (IMS) is a telecom-grade mechanism that addresses this important issue of future Internet. In the _Next Generation Network_ (NGN), IMS supports IP-based multimedia services through access networks including _Wideband Code Division Multiple Access_ (WCDMA), _Wireless Local Area Network_ (WLAN), CDMA2000, broadband IP network and fixed lines [1,2]. Figure 1 illustrates a simplified NGN/IMS network architecture. In this figure, the NGN/IMS network [Figures 1(a) and (b)] provides a standard approach to access the application network [Figure 1 (d)] from _User Equipment_ (UE) such as a mobile handset in the _Public Land Mobile Network_ [PLMN; Figure 1(c)] or a _Set-Top Box_ (STB)/TV in the broadband access network [Figure 1 (e)]. An example of PLMN network is _Universal Mobile Telecommunications System_ (UMTS) with the _General Packet Radio Service_ (GPRS) core network [1]. In Taiwan, Chunghwa Telecom has deployed the largest commercial NGN/IMS to provision enhanced voice, video, and Internet-based multimedia services. The capacity for this NGN/IMS network can accommodate about 500,000 subscribers in daily commercial operation [3]. Figure 1: The NGN/IMS Architecture. Based on NGN/IMS, we have developed the _Multimedia Middleware Adaptation System_ (MMAS) and _IPTV Convergence Server_ (IPTV-CS) [4,5] for location-based multimedia services with _Multimedia on Demand_ (MOD). MOD [6] is a commercial IPTV service that Chunghwa Telecom offers to over 800,000 subscribers with STBs. By integrating MOD [(9) in Figure 1] with NGN/IMS through the MMAS/IPTV-CS platform, we can offer enhanced IPTV services to MOD subscribers as well as mobile users when they are watching TV. Examples of the services are described below:  
1. **Weather Forecast Service** provides local weather, the weather forecast next week, international weather, satellite images, video forecasts, and so on. The service also offers special weather reports for, e.g., typhoons, low temperature, heavy rain, and earthquakes. In this service, users can set their favorite cities or obtain weather information of their current locations through the _Location Based Service_ (LBS). 2. **Dining Information Service** provides the menu/prices of dishes of a restaurant. The food description service allows a user to query neighborhood restaurant information, restaurant addresses and phone numbers. 3. **Music Video (MV) Information Service** allows a user to browse movie trailers and download music. 4. **Living Information Service** provides Lotto winning numbers and uniform-invoice prize winning numbers inquiries. 5. **Traffic Information Service** provides immediate road status, _Department of Rapid Transit System_ (DRTS) road maps, and timetables for airlines, _Taiwan High Speed Rail_ (THSR), Taiwan Railways, _etc._
6. **Health Care Information Service** provides neighborhood hospital information inquiry. 7. **My Service** provides user billing information. These services can be integrated with the click-to-talk function so that a user can talk directly to service representatives (e.g., a restaurant waitress) during access of the services. The above services can be directly deployed in the Internet. However, our commercial operation experiences indicate that implementing these services in NGN/IMS has several advantages. First, the users of these services can be directly identified by telephone numbers and can be authenticated through IMS with telecom-grade security and _Quality of Service_ (QoS) (see [7] for the implementation details).