Tutorial 1 1 Describe the difference between mobile

Tutorial 1 1. Describe the difference between "mobile communications" and "wireless communications". 2. List the challenges of mobile/wireless communications and give general ideas how to deal with the challenges. 3. Briefly describe the term “location-based services” and “context-aware services” 4. Check out the strategies of different network operators while migrating towards third generation systems. Why is a single common system not in sight?

1. Describe the difference between "mobile communications" and "wireless communications". n n n These two conceptions are not equal. But they have some intersection. Mobile IP belongs to mobile communication, while it is not necessarily wireless communication. IEEE 802. 16 defines Fixed Broadband Wireless Access systems which does not belong to mobile communication. Sensor networks are wireless but not mobile communication. GSM, CDMA base stations and 802. 11 access points are also wireless but not mobile communications

2. List the challenges of mobile/wireless communications and give general ideas how to deal with the challenges 1. 2. 3. 4. 5. 6. Communication challenge: q No stable connections & bandwidth-- fluctuated wireless channels and bandwidth shortage. Energy challenge Hardware challenge: q Small display; slow processor and limited size of memory etc. Interoperability challenge: q Data formats, codec and protocols may not be compatible Software and storage challenge: q limited storage capacity and processing power. Security challenge: q vulnerable to various attacks (wireless link, data access, store and privacy etc).

3. Briefly describe the term “location-based services” and “context-aware services” n Location-based services q q n Different services are provided based on different locations of the users (or at different places) Emphasized on data and information delivery (broadcast and dissemination of information) I. e. , shopping malls, schools, toilets What do you need when you are in a shopping mall? Context-aware services q Different services are provided based on different context detected in the system (situational)

4. Check out the strategies of different network operators while migrating towards third generation systems. Why is a single common system not in sight? n n n n n Today’s GSM operators add the new 3 G air interfaces of UMTS to their existing GSM/GPRS infrastructure networks. Current GSM/GPRS networks already offer packet and circuit switched data transmission following the Release 99 of UMTS. The operators have to install new radio access networks, i. e. , antennas, radio network controller etc. The situation is similar for operators using cdma. One (IS-95) technology. However, these operators go for WCDMA/cdma 2000 as this system allows them to reuse their already existing infrastructure. Thus, based on the separation of the mobile phone systems into (very roughly) CDMA and GSM. Operators will lead to two different major 3 G systems, cdma 2000 and UMTS (and their future releases). Right now, it does not seem that there is a place for a third 3 G system. Current TDMA operators might move to EDGE enhanced systems or join the UMTS system. However, it is still open what will happen in China –the Chinese system TDSCDMA was pushed by the government, but networks and devices are still missing. Currently, the majority of Chinese subscribers use GSM, some operators offer CDMA.