Transcript CDPD Service

CDPD Service
Liu ShuPing
Feng Yue
Current Situation Of Mobile Data
Communications
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Circuit-switched cellular technology.
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Packet-switched cellular technology
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TACS, AMPS, GSM and CDMA use now.
Occupying channel during the whole connection time
Each data gram is encapsulated and sent
packets individually.
Cellular Digital Packet Data technology
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Same Idea as Packet-Switched.
What Is CDPD
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A service?
A technology?
A network?
A standard?
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.
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.
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.
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!
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.
CDPD vs. GPRS
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CDPD’s real competitor is GPRS. Because of same time, same place,
similar service and targeted customers.
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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.
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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.
CDPD And GPRS Similarity
 Easy to enlarge the capacity.
 Small delay.
 Both security is high.
 GPRS: CS-1, CS-2.
 CDPD: Reed Solomon.
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.
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.
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.
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.
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.
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.
CDPD License In China.
No Auction
Impact Of WTO To CDPD Service
 More open market.
 Foreign capital can enter.
 Reduce the telecommunication service
tarriffs.
 Wellcome to invest!!!
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.
Wireless ATM Via CDPD
 More and more popular in China.
 Very convenient.
 CDPD provides reliable, fast and safe
access.
 Maintenance is not very high.