1. CELLULAR CONCEPTS AMIT SOROT EC-08007 ADVANCED GROUP OF INSTITUTION

2. Transmitting/receiving voice and data using electromagnetic waves in open space. The information from sender to receiver is carried over a well defined frequency band(channel). Each channel has a fixed frequency bandwidth & capacity(bit rate). Different channels can be used to transmit information in parallel and independently.

3. Transmitting signal Received signal satellite Transmitting antenna Receiving antenna

4. FM RADIO88 MHZ TV BROADCAST200 MHZ GSM PHONES900 MHZ GPS1.2 GHZ PCS PHONES1.8 GHZ BLUETOOTH2.4 GHZ Wi-Fi2.4 GHZ

5. Freedom from wires. No bunch of wires running from here and there. “Auto Magical” instantaneous communication without physical connection setup e.g.- Bluetooth, Wi-Fi. Global coverage Communication can reach where wiring is infeasible or costly e.g.- rural areas,buildings,battlefield,outerspace. Stay connected,flexiblity to connect multiple devices.

6. RADIO TRANSMISSION:- easily generated, Omni- directional, travel long distance, easily penetrates buildings. PROBLEMS:- frequency dependent, relatively low bandwidth for data communication, tightly licensed by government. MICROWAVE TRANSMISSION:- widely used for long distance communication, give high S/N ratio, relatively inexpensive. PROBLEMS:- don’t pass through buildings, whether and frequency dependent.

7. INFRARED AND MILIMETER WAVES:- widely used for short range communication, unable to pass through solid objects, used for indoor wireless LANs, not for outdoors. LIGHT WAVE TRANSMISSION:- unguided optical signal such as laser, unidirectional, easy to install, no license required. PROBLEMS:- unable to penetrate rain or thick fog, laser beam can be easily diverted by air.

8. CELLULAR SYSTEM WIRELESS LANs SATELLITE SYSTEM PAGING SYSTEM PANs(BLUETOOTH)

9. Definition Wireless communication technology in which several small exchanges (called cells) equipped with low-power radio antennas (strategically located over a wide geographical area) are interconnected through a central exchange. As a receiver (cell phone) moves from one place to the next, its identity, location, and radio frequency is handed-over by one cell to another without interrupting a call. Practical

10. High capacity is achieved by limiting the coverage of each base station to a small geographic region called a cell. Same frequencies timeslots/codes are reused by spatially separated base stations. A switching technique called handoff enables a call to proceed uninterrupted when one user moves from one cell to another. Neighboring base stations are assigned different group of channels so as to minimize the interference.

11. By systematically spacing base stations and the channel groups may be reuse as many number of times as necessary. MSC CELLS PSTN SUBSCRIBER UNIT BASE STATIONS Coverage area

12. BSC BS1 BS2 BS3 Connect to Bs1 & start calling Out of BS1 coverage & connect to BS2 Out of BS2 coverage & connect to BS3 Call ended

13. Cellular radio systems rely on intelligent allocation and reuse of channels throughout the coverage area. Each base station is allocated a group of radio channels to be used within the same geographical area of its cell. Neighboring base stations are given different channel allocation from each other. The design procedure of allocating channel groups for all of the cellular BS within a system is called frequency reuse or frequency planning.

14. Co channel cells

15. Co channels 60 degree u v D

16. Axes u and v intersect at 60 degree. Unit scale is the distance between center cells. If cell radius to point of hexagon is R then 2Rcos30=1 Or R = 1/√3. to find the distance of a point P(u, v) from the origin we use x-y to u-v coordinate transformation. R² = x² + y² x=ucos30˚ y=u+vsin30˚ r=√(v²+uv+u²)

17. Using this equation to locate co-channel cells we start from reference cell and moves i hexagon along u axis then j hexagon along the v axis. Hence the distance between co-channel cells in adjacent cluster is given by D = √(i²+ij+j²) The number of cells in a cluster N is given by N = √(i²+ij+j²) where i and j are integers. Hence the possible values of N are 1, 3, 4, 7, 12……

18. Formation of cluster for N=7 Suppose i=2 and j=1 will give co channel cell Same color showing co-channel cells. i=2 j-=1 Co channel cells

19. Global system for mobile communication is a set of ETSI standards specifying the infrastructure for a digital cellular services. GSM networks are structured hierarchically it consist of one administrative region which is assigned to a MSC. Each administrative region is made up of at least one location area (LA). LA is also called the visited area. An LA consists of several cell groups. Each cell group is assigned to a base station controller (BSC)

20. GSM NETWORK MSC REGION LOCATION AREA (LA) BS CONTROLLER CELL LA BS CONTROLLER BS CONTR -OLLER MSC REGION

21. BSC MSC EIR AUC HLR VLR ISDN PSTN OTHER NETWORKS BSS NSS NMS Mobile station

22. Consist of two main elements. 1. The mobile equipment 2. Subscriber identity module(SIM).

23. BSS = BSC + BTS 1.RADIO PATH CONTROL 2.AIR INTERFACE SIGNALLING 1.CENTRAL N/W ELEMENT OF BSS 2.CALL ESTABLISHMENT 3.MOBILITY MGMT 4.STATISTICAL RAW DATA COLLECTION 1.SPEECH PROCESSING 2.MODULATION/DE MODULATION 3.TRANSCODER 4.MINIMIZE TRANSMISSION PROBLEM 5.AIR INTERFACE MANAGEMENT

24. NSS = MSC + HLR + VLR + AUC + EIR MANAGE COMMUNICATION B/W USERS INCLUDE DATABASE TO STORE INFORMATION OF USER CALL CONTROL MOBILITY MGMT SUBSCRIBER DATA HANDLING CHECK IDENTITY OF USER PERMANENT STORAGE OF USER INFORMATION STORE A COPY OF HLR CHECK ROAMI NG PROVIDE AUTHENT ICATION SECURITY CHECK IMEI NUMBER OF MOBILE

25. 1. MONITORING 2.MANAGE 3.OPERATION 4. MAINTANENCE NMS

26. USE TDMA + FDMA MODULATION USED = GMSK(Gaussian minimum shift keying) UPLINK FREQUENCY = 890 – 915 MHZ DOWNLINK FREQUENCY = 935 – 960 MHZ

27. WLAN connect local computers Range (100 m) confined region Break data into packets Channel access is shared Backbone internet provides best service Poor performance in some application like videos Low mobility

28. Global coverage Different orbit height Optimized for good transmission Expensive base stations. Voice and data transmission Telecommunication application GPS, global telephone connection TV broadcasting, military, whether broadcasting

29. Broad coverage for short messages Message broadcast from all base stations Simple terminals Optimized for one way transmission Answer back hard Overtaken by cellular Pager system

30. PSTN Paging control center Paging terminal Terrestrial link Satellite link City 1 City 2 City N Base station

31. Bluetooth Cable replacement RF technology Short range(10m) 2.4 GHz band TDD duplex scheme 1 Mbps data rate shared b/w 7 devices Polling based multiple access Work on frequency hopping spread spectrum technology

32. Peer to peer communication No backbone infrastructure Routing can be multihop Topology is dynamic Fully connected with different link SINRs.

33. Ad-hoc network provides a flexible network infrastructure for many emerging applications. The capacity of such networks is generally unknown. Transmission, access and routing strategies for these networks are generally ad-hoc. Cross layer design is very critical and challenging. Energy constraints impose interesting design for trade offs communication and networking.