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CDPD Service

CDPD Service. Liu ShuPing Feng Yue. Current Situation Of Mobile Data Communications. Circuit-switched cellular technology. TACS, AMPS, GSM and CDMA use now. Occupying channel during the whole connection time Packet-switched cellular technology

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CDPD Service

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  1. CDPD Service Liu ShuPing Feng Yue

  2. Current Situation Of Mobile Data Communications • Circuit-switched cellular technology. • TACS, AMPS, GSM and CDMAuse now. • Occupying channel during the whole connection time • Packet-switched cellular technology • Each data gram is encapsulated and sent packets individually. • Cellular Digital Packet Data technology • Same Idea as Packet-Switched.

  3. What Is CDPD • A service? • A technology? • A network? • A standard?

  4. History Of AMPS • CDPD calls AMPS “mum”. • AMPS, originated in 1960s, born in 1980s. • Birth Place: Bell Lab. • 1983, AMPS speech service was availble in USA. • Run on 800MHz, why? • Lower for TV and FM. • Higher can not be used with that time technology. • Fundenmental success, the first wide spread public wireless, mobile, communication service and network.

  5. CDPD History. • In 1992, AT&T, MGcaw, BAM, SW Bell, North Telecom, Ameritech provided 1000,000us$ each to make a fund for data service. • In 1993, the first version of standard of CDPD came into view. • In 1994, in America, the first CDPD experimental network run. • CDPD ROUND TABLE: CDPD Forum was founded on April 1994. • CS-CDPD was born latter. Circuit Switch, only run by GTE, number 1800.

  6. Features Of CDPD • 19.2 kbps maximum throughput. Real user data is less than 12kbps. • Uses same frequency spectrum as AMPS. • Channel hopping. Two types. Purpose is to safe higher priority voice QoS. • TCP/IP Based. Very clever. Save cost, time, more reliable, compatible. • Dedicated Channels. AMPS voice channels lose. But it is a sign…. • Encryption over Airinterface like GSM. • DSMA-CD congestion control and MAC access. • Available in whole USA Now.

  7. CDPD Network Components • MDBS, Mobile Data Base Station, equal to the BTS in GSM. • air interface control • radio frequency management • automatic radio hopping. • MDIS, Mobile Data Intermediate Station. It partially combines the functions of BSC and MSC in GSM. • radio exchange, setting up the radio channels. • IS, Intermediate System. CDPD is an IP based system.CDPD backbone network is construed by the IS. We can say IS is also a router. • CDPD ES. M-ES and F-ES. • External F-ES is administered by CDPD subscribers. Internal F-ES is administered by the CDPD operators. NOTE!

  8. CDPD Network Service • Network Service is in term of Air Interface. • Domain Name Server. has its own web address translating mechanism. IS functions. • Subscriber Location Service. Not as accurate as GPS. Still enough. • Mobility Management Service. Each subscriber’s home MDIS tracks the her/his location. • Network Management Services. • Account Service. • Authentication Service.

  9. CDPD vs. GPRS • CDPD’s real competitor is GPRS. Because of same time, same place, similar service and targeted customers. • ADV: • Standarised earlier. • Operators have already invested a lot. • In America and Asia Pacific countries, it has in born adv, because AMPS. • At intial phase of service, cost for each subscriber is lower than GPRS. • DisADV: • GPRS 171.2kbps, CDPD 19.2kbps. • GPRS has much more larger capacity than CDPD. • GPRS uses TDMA GSM, but CDPD uses the FDMA AMPS. • GPRS can offer both Con-less, and Con-orient service, but CDPD only can provide Con-less service. • GPRS supports both IPv4 and IPv6. However, the CDPD only support IPv4. Less security, and address space.

  10. CDPD And GPRS Similarity • Easy to enlarge the capacity. • Small delay. • Both security is high. • GPRS: CS-1, CS-2. • CDPD: Reed Solomon.

  11. Attractiveness And Problems at America • Attractiveness: Based on TCP/IP, easy to check email. • Problem1: Different competitor-operators need to provide CDPD service. • Problem2: It was too expensive. 80$ 1MB. • Problem3: Software did not run well. • Problem4: Wireless transmission problem. • But Now, most of them are not new problems.

  12. Business Of CDPD In American Market • Giants: AT&T, Bell Atlantic, AT&T Wireless. Too Big. “ Trust” characteristics. • Now, CDPD is facing competition from GPRS service from same fathers even in its’ birth place. • My opinion, is because its’ rate is much slower compared with GPRS, HSCSD.

  13. The CDPD Business In Latin America • Tele2000 runs CDPD service in Latin American countries. Peru, Chile…. • They prefer the most economic solution. • Tele2000 runs the service jointly with AT&T in Latin America.

  14. CDPD Applications • Transportation: Ambulance, dispatch system. • Public security: Policemen can access the latest database in real time to. E.g. Check suspected person, Verify identity. Check the car current status. • Remote measurement: Remote control. • Commerce. Wireless ATM. Wireless Credits Card Authentication. Mobile Payment. Adv of CDPD used in commerce field. • Implementing easily. • High speed. CDPD modem set up time is much faster than wire dial up modem. Even CDPD is 19.2kbps, wire dial up modem is 33.6kbps. • Reliable and Safety with strong encryption algorithm. • Personal use which covers the main part of the CDPD usage.

  15. CDPD In Chinese Market • Development History Of CDPD In China Mainland. • CDPD In China Hong Kong. • M499.com is the only CDPD operator in Hong Kong. • Grab the gap before the 3G. • The market is not so big, but achievements. • Want to find huge local operator to do joint. I am not optimistic. • So M499.com comes to China Mainland to make money.

  16. The Relation Between CDPD And Other PLMN Network In China • HSCSD’s advantage is its’ transmission of large amount data. But CDPD is not suitable for this. • It can be realized that smooth connection between CDPD and narrow band CDMA. • Mobitex is from Ericsson. It is too slow. 8Kbps raw data. • CDPD is also face the new Wi-Fi Chanllenge. Because it is much faster than CDPD. • WAP is even more technical advanced, why lost game in China. • Few content. • Too expensive, twice more expensive than CDPD.

  17. CDPD License In China. No Auction

  18. Impact Of WTO To CDPD Service • More open market. • Foreign capital can enter. • Reduce the telecommunication service tarriffs. • Wellcome to invest!!!

  19. Current CDPD Operators In China • China Telecom. Has the position of AS&T in USA. • Shang Hai P&T Mobile Data Communication Co. Ltd. • But it seems they will not invest any more to the CDPD public service. Because our 2G systems are mainly GSM.

  20. Wireless ATM Via CDPD • More and more popular in China. • Very convenient. • CDPD provides reliable, fast and safe access. • Maintenance is not very high.

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