WIRELESS ATM BY SAIKIRAN PANJALA
- 1. Presented by ----------- (1#########) Under the guidance of --------------
- 2. Wireless and ATM ( Asynchronous Transfer Mode) are in it's infancy. No standards have been defined by either the ATM Forum or ITU-T, yet. Research have been going on to develop a protocol that will run on wireless medium without much delay and errors. ATM-type wireless networks will play an important role in the broadband communications network of the future
- 3. Since the late seventies, we have been watching movies and television serials, in which people are using mobile equipment to communicate and exchange multimedia traffic over small, handheld portable equipment. But now, due to the advent of high speed networks ( such as ATM), and recent advancement in mobile communications, visions of past are fast in reality.
- 4. Wireless systems are emerging, and the industry is still in it's infancy. Currently, wireless LAN technologies consists of infrared (IR), and microwave radio, ranging from frequencies in the region of GHz in Europe to infrared frequencies. Some of the wireless technologies are: 1. Spread Spectrum (CDMA) 2. Time Division Multiple Access (TDMA)
- 5. ATM ( Asynchronous Transfer Mode) has been advocated as an important technology for the wide area interconnection of heterogeneous networks. In ATM networks, the data is divided into small, fixed length units called cells. The cell is 53 bytes. Each cell contain a 5 byte header which consists of identification, control priority and routing information. The rest 48 bytes are the actual data.
- 6. ATM switches support two kinds of interfaces: User-network interface (UNI) :UNI connects ATM end systems (hosts, routers etc.) to an ATM switch. Network-node interface (NNI):NNI may be imprecisely defined as an interface connection between two ATM switches together . The ITU-T Recommendation requires that an ATM connection be identified with connection identifiers that are assigned for each user connection in the ATM network.
- 7. There are two fundamental types of ATM connections Permanent Virtual Connections (PVC):A PVC is a connection set up by some external mechanism, typically network management, in which a set of switches between an ATM source and destination ATM systems are programmed with the appropriate VPI/VCI values. PVCs always require some manual configuration
- 8. Switched Virtual Connections (SVC):An SVC is a connection that is set up automatically through signaling protocol. SVCs does not require the manual interaction needed to set up PVCs and, as such, are likely to be much more widely used. All higher layer protocols operating over ATM primarily uses SVCs.
- 9. Since the beginning, the concept of ATM is end-to-end communications i.e. in a Wide Area Network environment, the communication protocol will be the same i.e. ATM, and companies will no longer have to buy extra equipment ( like routers or gateways) to interconnect their LANs( local area networks). Also, ATM is considered to reduce the complexity of the network and improve the flexibility while providing end-end consideration of traffic performance
- 10. The concept of Wireless ATM is Radio ATM + Mobile ATM
- 11. 11 ATM Wireless ATM Radio ATM Mobile ATM ATM Switch ATM Gateway Switch Data base
- 12. Architecture: The architecture proposed by most researchers, composed of a large number of small transmission cells, called Pico cells. Each Pico cell is served by a base station. All the base station in the network are connected via the wired ATM network.
- 14. To avoid hard boundaries between Pico-cells, the base stations can operate on the same frequency. The basic role of the base station is interconnection between the LAN or WAN and the wireless subnets, and also to transfer packets and converting them to the wired ATM network from the mobile units.
- 15. ATM Switching System
- 16. Network Location and Connection Establishment: In order to establish connections between the mobile unit and the base station, the mobile must be located. Searching and registration can cause some problems. 1.Searching: Involves a form of broadcast in which the whole network is queried. 2.Registration: Objects are responsible for their own registration at a well known registration point.
- 17. I have tried to analyze different issues discuss to Wireless ATM, and discussed some of the ideas of different researchers working on it. Wireless and ATM, both are relatively new field, and are still in it's infancy. No standards have been set for Wireless ATM. ATM-type wireless networks will play an important role in the broadband communications networks of the future.
- 18. Thank you