CDPD Cellular Digital Packet Data What Is CDPD

CDPD: Cellular Digital Packet Data

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

Introduction • In 1993, the first version of standard of CDPD came into view. • In 1994, in America, the first CDPD experimental network run. • CDPD offer one of the most advanced means of wireless data transmission technology. • CDPD transmits digital packet data at 19. 2 Kbps. • CDPD system allow user to transmit data with a higher degree of accuracy, strong security, and few service interruption

CDPD Definition • CDPD is a technique for quick transfer of data. • It transmitts data at 19. 2 kbps. • It transmitt the packet over the cellular network in a reliable manner. • In 1993, the first version of standard of CDPD came into view. • In 1994, in America, the first CDPD experimental network run.

Key CDPD Characteristics 1. Availability: Identifies whether CDPD services can be acquired from a carrier in a given region 2. Coverage: Identifies whether CDPD transmission can reach users in a given region. 3. Reliability: Identifies whether user can access and use CDPD services during congestion or network disruption 4. Transmission Speed: Describe the end to end data speed, including call setup time & transmission speed

Key CDPD Characteristics 5. Privacy and Security: Describe the level of inherent privacy and security of the service and the capability to add security measure 6. Cost: Characterizes the cost typical of CDPD service.

Features 1. 2. 3. 4. 5. 6. 7. 8. 9. Same Coverage as cellular system Schedule data packets to unused voice channel 19. 2 Kbps raw data transfer rate. Full duplex transreciever 600 mw transmit power Integrated TCP/IP protocol stack Compact size Strong aluminum case LED’s show status of CDPD operation

Working Of CDPD • It uses Channel Hopping Technique. • Initiates data transmission • Location Of available channel to establish data link. • Mobile data unit transmit data packets. • CDPD technology transmits chunks or packets of data • Equipment : 1) CDPD Modem 2) User terminal

User Equipment 1. CDPD Modem: • It Includes wireless antenna and modem that provides compatibility with network. • It can be internal or external. 2. User Terminal: • Any device that supports IP-based data communication can use CDPD. • Examples are as notebook or laptop Personal Computers (PCs), handheld computers or PCs.

Interfaces • A Interface : Air interface • I Interface : Intermediate system interface • E Interface : External interface

Components 1. Mobile End System ( M-ES) • Mobile computing device which has a cdpd modem built-in or attached • It support mac functionality • It transmit data over the airlink to MDBS • It should provide transparent interface to the user application • Example is CDPD modem

Components 2. Mobile data base station (MDBS) • It located at the cell site. • It is responsible for R. F management • It provide hop to hop control over the air interface • It controls the hop & RF segment between the M -ES and the cdpd network • Cellular geographic area control by MDBS

Components 3. Mobile Data Intermediate System(MDIS) • • • MDIS routs data packet to and from the CDPD N. W & the M-ES appropriately It validates M-ES using encryption keys for secure transmission of data It is responsible for IP routing An MDIS may serve single or multiple CGSA cells It can provides mobile home & serving functions

Components 4. INTERMEDIATE SYSTEM (IS) • It is the standard IP router • It routes the data through IP & CLNP, N. W • The IS components are the backbone of CDPD mesh

Components • • • 5. FIXED END SYSTEM (F- ES) F-ES is the final destination of message sent from M-ES F-ES received the data & process it appropriately The F-Es can be one of many stationary computing devices such as host computer , UNIX workstation

CDPD - Layering Application Transport Network Data link Physical Network layer IP/CLNP Connectionless Network Protocol SNDCP Subnetwork Dependant Convergence Protocol MDLP Mobile Data Link Protocol MAC Media Access Control Physical CDPD Layer

Mobile Data Link Protocol • It provides logical link control services between Mobile End Systems and Mobile Data Intermediate Systems. • The purpose of MDLP is to transmit information between network layer entities across the CDPD Air link interface. • High-level data link control (HDLC) • Temporary equipment identifier (TEI) • Identifies destination mobile - virtual address.

Subnetwork Dependent Convergence Protocol Encryption/decryption User data confidentiality SNDCP provides a number of services to the network layer Compression/elimination of redundant protocol control information

Mobile Network Registration Protocol Exchange of routing and registration information between the M-ES and a serving MD-IS. Delivery of authentication information about an M -ES. Registration and Authentication of multicast NEI.

Radio Resource Management It prevents interference of radio channel and other wireless communication characteristic. RRM concerns multi-user and multi-cell network capacity issues, rather than point-to-point channel capacity. The objective of radio resource management is to maximize the system spectral efficiency in bit/s/Hz/base station site or Erlang/MHz/site.

Application of CDPD • • Credit card verification ATM network 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.

Application of CDPD • Implementing easily. • High speed. CDPD modem set up time is much faster than wire dial up modem. Even CDPD is 19. 2 kbps, wire dial up modem is 33. 6 kbps. • Reliable and Safety with strong encryption algorithm. • Personal use which covers the main part of the CDPD usage.

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

References • • • http: //en. wikipedia. org/wiki/Radio_resource_ma nagement http: //www. protocols. com/pbook/cdpd. htm http: //www. amycsizmardalal. com/research/CDP D/intro. html http: //www. webtechniques. com/archives/2001/1 1/jepson/ http: //en. wikipedia. org/wiki/Fleet_management http: //www. buzzle. com/editorials/8 -29 -200458574. asp