B.B.S COLLEGE OF ENGG & TECHNOLOGY ALLAHABAD REPORT ON MOBILE COMPUTING SUBMITTED BY SAURABH SRIVASTAVA CSE III’rd YEAR 0813810070 CERTIFICATE This is certify that B.TECH 3’rd year seminar report entitled MOBILE COMPUTING is a bonafide record of work carried out under the supervision of ER. K.K TRIPATHI & ER. M.K MISHRA. The 3’rd year student of CSE B.TECH studying at B.B.S COLLEGE OF ENGG & TECHNOLOGY ALLAHABAD affiliated to G.B.T.U. HEAD OF DEPARTMENT SEMINAR INCHARGE DR.S.B.L ASTHANA ER. K.K.TRIPATHI & ER. M.K. MISHRA CONTENTS 1. INTRODUCTION 1.1-WHAT IS MOBILITY? 1.2-EVOLUTION 1.3-BASE TECHNOLOGY 1.3.1-FDMA 1.3.2-TDMA 1.3.3-CDMA 1.4-WI-FI TECHNOLOGY 2. RELATIONSHIP 2.1 -NOMADIC 2.2 -MOBILE 2.3 –UBIQITOS 3. ASPECTS 3.1-MOBILE HARDWARE 3.2-MOBILE SOFTWARE 3.3-MOBILE COMMUNICATION 4. RELETED TECHNOLOGY 4.1-Mobile IP MANET BLUETOOTH 4.2-ROUTING PROTOCOL 4.2.1-PROACTIVE 4.2.1- REACTIVE 4.2.2- HYBRID 5Multiple Access collision avoidance 6.EVOLUTION MATRICS 6.1-PACKET DELIVERY RATIO 6.2-ROUTING OVERHEAD 6.3-PATH OPTIMALITY 7. DESTINATION SEQUENCED DISTENCE VECTOR 7.1-DESION ASSUMPTION 7.2-MORE ON D.S.D.V 7.3-PROBLEM WITH D.S.D.V 7.4-PERFORMANCE OF D.S.D.V 8. DYNAMIC SOURCE ROUTING 8.1-ROUTE MAINTENANCE IN DSR 8.2-PERFORMANCE OF DSR 8.3-CLUSTER 9. COMPARISON 9.1-D.S.D.V & DSR 9.2-WIRELESS TECHNOLOGY 9.3-WIRE NETWORK & MOBILE NETWORK 10. FORMATION OF TECHNOLOGY 10.1.1-BLUETOOTH 10.1.2.-SCATTERNET 10.1.3-PICONET 10.2- ASYMMETRIC LINK FORMATION PROCEDURE 11. NUMBER OF CELL PHONE US 93-2002 12. TOPOLOGY CONSTRUCTION 12.1-BLUETOOTH TOPOLOGY CONSTRUCTION PROTOCOL 12.2-ASSUMPTION IN BTCP 13. DECISION 13.1-WHAT IS THE CHALLENGE 13.2-OPTIMIZATION 13.3-OUR SOLUTION 14. MAIN IDEA 14.1-APPLICATION 14.2-FETURE 14.3-LIMITATION 1.1What is Mobility? A device/person that moves between different � Geographical locations � Networks � Communication devices � Applications � Examples: � Plug in laptop at home/work on Ethernet � Cell phone with access to cellular network � networked PDA 1.2HISTORY (1920-1945) 1920: Discovery of short waves by Marconi – reflection at the ionosphere – smaller sender and receiver – Possible with vacuum tube • 1926: First phone on a train – Hamburg – Berlin – wires parallel to the railroad track • 1926: First car radio • 1928: First TV broadcast – John L. Baird (1888 – 1946) – Atlantic, color TV – WGY Schenectady • 1933: Frequency modulation – Edwin H. Armstrong (1890 – 1954) HISTORY (1945-1980) 1958: German A-Netz – Analog, 160MHz, connection setup only from mobile station, no handover, 80% coverage, 16kg, 15k Marks – 1971: 11000 customers – Compare with PTT (Swisscom) NATEL: 1978 – 1995, maximum capacity 4000, which was reached 1980 • 1972: German B-Netz – Analog, 160MHz, connection setup from the fixed network too (but location of the mobile station has to be known) – available also in A, NL and LUX, 1979 13000 customer in D – PTT NATEL B: 1984 – 1997, maximum capacity 9000 • 1979: NMT Nordic Mobile Telephone System – 450MHz (Scandinavia HISTORY (1980-TODAY) 1996: HiperLAN – High Performance Radio Local Area Network – Products? • 1997: Wireless LAN – IEEE 802.11 – 2.4 – 2.5 GHz and infrared, 2Mbit/s – already many products (with proprietary extensions) • 1998: Specification of GSM successors – GPRS is packet oriented – UMTS is European proposal for IMT-2000 • 1998: Iridium – 66 satellites (+6 spare) – 1.6GHz to the mobile phone 1.3- BASE TECHNOLOGY Isolates data from different sources � Three basic choices � Frequency division multiple access (FDMA) � Time division multiple access (TDMA) � Code division multiple access (CDMA) 1.3.1- FDMA Simplest � Best suited for analog links � Each station has its own frequency band, separated by guard bands � Receivers tune to the right frequency � Number of frequencies is limited � reduce transmitter power; reuse frequencies in non-adjacent cells � example: voice channel = 30 KHz 1.3.2 TDMA All stations transmit data on same frequency, but at different times � Needs time synchronization � Pros � users can be given different amounts of bandwidth � mobiles can use idle times to determine best base station � can switch off power when not transmitting � Cons � synchronization overhead � greater problems with multipath interference on wireless links 1.3.3 CDMA Pros � hard to spy � immune from narrowband noise � no need for all stations to synchronize � no hard limit on capacity of a cell � all cells can use all frequencies � Cons � implementation complexity � need for a large contiguous frequency band (for direct sequence) : 1.4 WI-FI TECHNOLOGY In the field � In your garden � Remote access to important data � Meetings (e.g., quick access to statistics, reports) � Law Enforcement and Medical Emergencies � Information Services (Yellow Pages) � While touring a new city • Where am I? What is this building? How do I get to Lane Avenue? I’m hungry! � E-books � Weather, Traffic, Sports, Entertainment � In the grocery store � Ubiquitous communication � email, Web � voice � Video � Sales and Mobile Office 2. RELATIONSHIP 2.1 NOMEDIC Nomadic computing: “portable”; no mobility while connected 2.2 MOBILE Mobile computing: “on-the-go”, e.g., while sitting on a train; possibility of network connections remaining open 2.3 UBIQUITOS computing everywhere 3 .ASPECTS 3.1-MOBILE HARDWARE That deals with physical aspect . 3.2- MOBILE SOFTWARE- That deals with aapplication of software. 3.3 MOBILE COMMUNICATION That have to need of some protocol. The protocol is set of rules . 4.RELETED TECHNOLOGY 4.1-Mobile IP MANET BLUETOOTH 4.2-ROUTING PROTOCOL 4.2.1-PROACTIVE � strive to have route info ready when needed � lots of router traffic � low routing latency 4.2.1- REACTIVE(ON DEMAND) � compute route when needed � less router traffic � high routing latency 4.2.3HYBRID(PRO/REACTIVE) 5.MACA - Multiple Access collision avoidance � Uses short signaling packets for collision avoidance. � RTS (request to send): a sender request the right to send from a receiver with a short RTS packet before it sends a data packet. � CTS (clear to send): the receiver grants the right to send as soon as it is ready to receive. � If CTS is not heard, or RTS collides, then random backoff � Signaling packets contain � sender address � receiver address � packet size � Variants of this method can be found in 6.EVOLUTION MATRICS 6.1PACKET DELIVERY RATIO describes the “loss rate" seen by transport layer 6.2 ROUTING OVERHEAD determines scalability, performance in lowbandwidth/ congested environments, battery consumption... 6.3 PATH OPTIMALITY packets sent by applications vs. # packets received 7.DESTINATION SEQUENCED DISTENCE VECTOR Each node periodically broadcast its route table � increments sequence number of route to itself each time � If a directly connected link is down: � set cost of all route-table entries using that link to inifinity and add one to their sequence numbers � broadcast route table immediately (self route’s sequence number also incremented) � When receiving route table: � accept entries containing sequence numbers at least as large as one’s own � accept entries with equal sequence numbers but with lower cost. 7.1 DESION ASSUMPTION What is your physical environment? � how many nodes? � do nodes move? � how often? � how quickly? � radio attenuation model? � “reference distance" (e.g., 100m) � free space propagation, 2-ray ground reflection, ... � Medium Access Control � carrier sense (physical, virtual) � acknowledgement mechanism � Packet Buffering � how long can a node wait before sending? � how long can a node wait before forwarding 7.2 MORE ON DSDV Routing-table updates � incremental when frequent � full when infrequent � After changes � best path might not arrive first � delay propagating changes to wait till best one arrives � but use most-recent information for routing packets locally � keep track of how long this takes 7.3 PROBLEM WITH DSDV Control-message overhead grows as O(n2) � much activity as a node moves in or out of range � happens even if no one wants to communicate with it � Each node must have complete table 7.4 PERFORMANCE Simulation results � fails to converge if nodes don't pause for at least 300 seconds during movement � 70%-92% delivery ratio at higher rate of mobility � lost packets due to stale routing entries � routing overhead is constant with respect to mobility rate (periodic protocol) � nearly optimal path selection .8 . DYNAMIC SOURCE ROUTING Problems with traditional routing protocols � large, periodic updates are wasteful � redundant information � waste bandwidth � waste battery power � topology changes may involve more than link 8.1 ROUTE MAINTENANCE IN DSR If 2 nodes listed next to each other in route move out of range � return route error message to sender � sender can use another route in its routing cache � sender can invoke Route Discovery again 8.2PERFORMANCE IN DSR Simulation results � packet delivery ratio is independent of traffic load (greater than 95%) � incremental cost of adding new sources decreases as sources are added � can re-use information about other routes � scoping of route requests via route cache � nearly optimal path selection 8.3 CLUSTER Based on DSDV. � To find a set of clusters to cover whole MANET. � A cluster is a subset of nodes which can communicate with a cluster head and with nodes in cluster. Diameter of a cluster is 2. � Cluster formation policy: � ID ( Lowest ID ) � Connectivity ( Highest Connectivity ) � Mobility ( MOBIC Clustering ). 9.COMPRASION 9.1 DSDV & DSR DSDV performs predictably • delivers virtually all data packets... .. for low node