CDPD ServiceCDPD Service

Liu ShuPingLiu ShuPing

Feng YueFeng Yue

Current Situation Of Mobile Data Current Situation Of Mobile Data CommunicationsCommunications

Circuit-switched cellular technology.Circuit-switched cellular technology. TACS, AMPS, GSM and CDMATACS, AMPS, GSM and CDMA use now.use now. Occupying channel during the whole connection timeOccupying channel during the whole connection time

Packet-switched cellular technologyPacket-switched cellular technology Each data gram is encapsulated and sent Each data gram is encapsulated and sent

packets individuallypackets individually..

Cellular Digital Packet Data technologyCellular Digital Packet Data technology Same Idea as Packet-Switched.Same Idea as Packet-Switched.

What Is What Is CDPDCDPD

A service?A service? A technology?A technology? A network?A network? A standard?A standard?

History Of AMPSHistory Of AMPS

CDPD calls AMPS “mum”.CDPD calls AMPS “mum”. AMPS, originated in 1960s, born in 1980s.AMPS, originated in 1960s, born in 1980s. Birth Place: Bell Lab.Birth Place: Bell Lab. 1983, AMPS speech service was availble in USA.1983, AMPS speech service was availble in USA. Run on 800MHz, why?Run on 800MHz, why?

Lower for TV and FM.Lower for TV and FM. Higher can not be used with that time Higher can not be used with that time

technology.technology. Fundenmental success, the first wide spread Fundenmental success, the first wide spread

public wireless, mobile, communication service public wireless, mobile, communication service and network.and network.

CDPD History.CDPD History.

In 1992, In 1992, AT&T, MGcaw, BAM, SW Bell, North Telecom, AT&T, MGcaw, BAM, SW Bell, North Telecom, Ameritech provided 1000,000us$ each to make a fund Ameritech provided 1000,000us$ each to make a fund for data service.for data service.

In 1993, the first version of standard of CDPD came In 1993, the first version of standard of CDPD came into view.into view.

In 1994, in America, the first CDPD experimental In 1994, in America, the first CDPD experimental network runnetwork run..

CDPD ROUND TABLE: CDPD Forum was founded on CDPD ROUND TABLE: CDPD Forum was founded on April 1994. April 1994.

CS-CDPD was born latter. Circuit Switch, only run by CS-CDPD was born latter. Circuit Switch, only run by GTE, number 1800.GTE, number 1800.

Features Of CDPDFeatures Of CDPD

19.2 kbps maximum throughput. Real user data is less than 12kbps.19.2 kbps maximum throughput. Real user data is less than 12kbps. Uses same frequency spectrum as AMPS.Uses same frequency spectrum as AMPS. Channel hopping. Two types. Purpose is to safe higher priority voice Channel hopping. Two types. Purpose is to safe higher priority voice

QoS.QoS. TCP/IP BasedTCP/IP Based. Very clever. Save cost, time, more reliable, compatible.. Very clever. Save cost, time, more reliable, compatible.

Dedicated ChannelsDedicated Channels. . AMPS voice channels lose. But it is a sign….AMPS voice channels lose. But it is a sign…. Encryption over Airinterface like GSM.Encryption over Airinterface like GSM. DSMA-CD congestion control and MAC access.DSMA-CD congestion control and MAC access. Available in whole USA Now.Available in whole USA Now.

CDPD Network ComponentsCDPD Network Components

MDBS, Mobile Data Base Station, equal to the BTS in GSM.MDBS, Mobile Data Base Station, equal to the BTS in GSM. air interface controlair interface control radio frequency management radio frequency management automatic radio hopping. automatic radio hopping.

MDIS, Mobile Data Intermediate Station. It partially combines the MDIS, Mobile Data Intermediate Station. It partially combines the functions of BSC and MSC in GSM.functions of BSC and MSC in GSM.

radio exchange, setting up the radio channelsradio exchange, setting up the radio channels.. IS, Intermediate System. CDPD is an IP based system.IS, Intermediate System. CDPD is an IP based system. CDPD CDPD

backbone network is construed by the IS. We can say IS is also a backbone network is construed by the IS. We can say IS is also a router.router.

CDPD ES. M-ES and F-ES.CDPD ES. M-ES and F-ES. External F-ES is administered by CDPD subscribers. Internal F-ES is External F-ES is administered by CDPD subscribers. Internal F-ES is

administered by the CDPD operators. NOTE!administered by the CDPD operators. NOTE!

CDPD Network ServiceCDPD Network Service

Network Service is in term of Air Interface.Network Service is in term of Air Interface. Domain Name ServerDomain Name Server. . has its own web address has its own web address

translating mechanism. IS functions. translating mechanism. IS functions. Subscriber Location Service. Not as accurate as Subscriber Location Service. Not as accurate as

GPS. Still enough.GPS. Still enough. Mobility Management Service.Mobility Management Service. Each subscriber’s Each subscriber’s

home MDIS tracks the her/his location.home MDIS tracks the her/his location. Network Management Services.Network Management Services. Account Service.Account Service. Authentication Service.Authentication Service.

CDPD vs. GPRSCDPD vs. GPRS

CDPD’s real competitor is GPRS. Because of same time, same place, similar CDPD’s real competitor is GPRS. Because of same time, same place, similar service and targeted customers.service and targeted customers.

ADV: ADV: Standarised earlier.Standarised earlier. Operators have already invested a lot.Operators have already invested a lot. In America and Asia Pacific countries, it has in born adv, because In America and Asia Pacific countries, it has in born adv, because

AMPS.AMPS. At intial phase of service, cost for each subscriber is lower than GPRS.At intial phase of service, cost for each subscriber is lower than GPRS.

DisADV:DisADV: GPRS 171.2kbps, CDPD 19.2kbps.GPRS 171.2kbps, CDPD 19.2kbps. GPRS has much more larger capacity than CDPD.GPRS has much more larger capacity than CDPD. GPRS uses TDMA GSM, but CDPD uses the FDMA AMPS.GPRS uses TDMA GSM, but CDPD uses the FDMA AMPS. GPRS can offer both Con-less, and Con-orient service, but CDPD only GPRS can offer both Con-less, and Con-orient service, but CDPD only

can provide Con-less service.can provide Con-less service. GPRS supports both IPv4 and IPv6. However, the CDPD only support GPRS supports both IPv4 and IPv6. However, the CDPD only support

IPv4. Less security, and address space.IPv4. Less security, and address space.

CDPD And GPRS SimilarityCDPD And GPRS Similarity

Easy to enlarge the capacity.Easy to enlarge the capacity. Small delay.Small delay. Both security is high.Both security is high.

GPRS: CS-1, CS-2.GPRS: CS-1, CS-2. CDPD: Reed Solomon.CDPD: Reed Solomon.

Attractiveness And Problems at AmericaAttractiveness And Problems at America

Attractiveness: Based on TCP/IP, easy to check Attractiveness: Based on TCP/IP, easy to check email.email.

Problem1: Different competitor-operators need to Problem1: Different competitor-operators need to provide CDPD service.provide CDPD service.

Problem2: It was too expensive. 80$ 1MB.Problem2: It was too expensive. 80$ 1MB. Problem3: Software did not run well.Problem3: Software did not run well. Problem4: Wireless transmission problem.Problem4: Wireless transmission problem. But Now, most of them are not new problems.But Now, most of them are not new problems.

Business Of CDPD In American Business Of CDPD In American MarketMarket

Giants: Giants: AT&T, AT&T, Bell Atlantic, AT&T Wireless. Too Bell Atlantic, AT&T Wireless. Too Big. “ Trust” characteristics. Big. “ Trust” characteristics.

Now, CDPD is facing competition from GPRS Now, CDPD is facing competition from GPRS service from same fathers even in its’ birth place.service from same fathers even in its’ birth place.

My opinion, is because its’ rate is much slower My opinion, is because its’ rate is much slower compared with GPRS, HSCSD.compared with GPRS, HSCSD.

The CDPD Business In Latin AmericaThe CDPD Business In Latin America

Tele2000 runs CDPD service in Latin American Tele2000 runs CDPD service in Latin American countries. Peru, Chile….countries. Peru, Chile….

They prefer the most economic solution.They prefer the most economic solution. Tele2000 runs the service jointly with AT&T in Tele2000 runs the service jointly with AT&T in

Latin America.Latin America.

CDPD ApplicationsCDPD Applications

Transportation: Ambulance, dispatch system.Transportation: Ambulance, dispatch system. Public security: Policemen can access the latest database in real time Public security: Policemen can access the latest database in real time

to. E.g. Check suspected person, Verify identity. Check the car current to. E.g. Check suspected person, Verify identity. Check the car current status.status.

Remote measurement: Remote control.Remote measurement: Remote control. Commerce. Wireless ATM. Wireless Credits Card Authentication. Commerce. Wireless ATM. Wireless Credits Card Authentication.

Mobile Payment. Adv of CDPD used in commerce field.Mobile Payment. Adv of CDPD used in commerce field. Implementing easily.Implementing easily. High speed. CDPD modem set up time is much faster than wire dial up modem. 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.Even CDPD is 19.2kbps, wire dial up modem is 33.6kbps. Reliable and Safety with strong encryption algorithm.Reliable and Safety with strong encryption algorithm.

Personal use which covers the main part of the CDPD usage.Personal use which covers the main part of the CDPD usage.

CDPD In Chinese MarketCDPD In Chinese Market

Development History Of CDPD In China MainlandDevelopment History Of CDPD In China Mainland.. CDPD In China Hong KongCDPD In China Hong Kong. .

M499.com is the only CDPD operator in Hong Kong.M499.com is the only CDPD operator in Hong Kong. Grab the gap before the 3G.Grab the gap before the 3G. The market is not so big, but achievements.The market is not so big, but achievements. Want to find huge local operator to do joint. I am not Want to find huge local operator to do joint. I am not

optimistic.optimistic. So M499.com comes to China Mainland to make So M499.com comes to China Mainland to make

money.money.

The Relation Between CDPD And The Relation Between CDPD And Other PLMN Network In ChinaOther PLMN Network In China

HSCSD’s advantage is its’ transmission of large amount HSCSD’s advantage is its’ transmission of large amount data. But CDPD is not suitable for this.data. But CDPD is not suitable for this.

It can be realized that smooth connection between CDPD It can be realized that smooth connection between CDPD and narrow band CDMA.and narrow band CDMA.

MobitexMobitex is from Ericsson. It is too slow. 8Kbps raw data. is from Ericsson. It is too slow. 8Kbps raw data. CDPD is also face the new Wi-Fi Chanllenge. Because it is CDPD is also face the new Wi-Fi Chanllenge. Because it is

much faster than CDPD.much faster than CDPD. WAP is even more technical advanced, why lost game in WAP is even more technical advanced, why lost game in

China.China. Few content.Few content. Too expensive, twice more expensive than CDPD.Too expensive, twice more expensive than CDPD.

CDPD License In China.CDPD License In China.

No AuctionNo Auction

Impact Of WTO To CDPD ServiceImpact Of WTO To CDPD Service

More open market.More open market. Foreign capital can enter.Foreign capital can enter. Reduce the telecommunication service Reduce the telecommunication service

tarriffs.tarriffs. Wellcome to invest!!!Wellcome to invest!!!

Current CDPD Operators In ChinaCurrent CDPD Operators In China

China TelecomChina Telecom. Has the position of AS&T in USA.. Has the position of AS&T in USA. Shang Hai P&T Mobile Data Communication Co. Shang Hai P&T Mobile Data Communication Co.

LtdLtd.. But it seems they will not invest any more to the But it seems they will not invest any more to the

CDPD public service. Because our 2G systems CDPD public service. Because our 2G systems are mainly GSM.are mainly GSM.

Wireless ATM Via CDPDWireless ATM Via CDPD

More and more popular in China.More and more popular in China. Very convenient.Very convenient. CDPD provides reliable, fast and safe CDPD provides reliable, fast and safe

access.access. Maintenance is not very high.Maintenance is not very high.