Token Ring and Client-Server• Token Ring– 1984 IBM introducedwith 4Mbits/sec– High quality and robust– Huge cost– IEEE 802.5• Client Server– Replaces largestMainframes– Client in front end– Server in the back end– Servers are powerful andclients were weaker thanservers
Peer to Peer• All machines have equivalent capabilities andresponsibilities• Through a hub or bus, all the computers areconnected• Considerable success in short time• Napster mp3 music file sharing application live in1999 and more than 20 million subscribers by mid2000
Wireless Local Area Network (WLAN)• IEEE 802.11 in 1997• Wi-Fi is also one such use.• Successful since all the personal computinglaptops comes with this.• There are so many standards like802.11a,b,c,d,e,…n
Bluetooth• initiated in 1998 and standardized by the IEEE as WirelessPersonal Area Network (WPAN) specification IEEE 802.15.• Bluetooth is a short range RF technology.• Bluetooth uses the unlicensed 2.4 GHz band and cantransmit data up to 1Mbit/s, can penetrate solid non-metalbarriers, and has a nominal range of 10m that can beextended to 100m.• Currently, Bluetooth development kits can be purchasedfrom a variety of suppliers, but the systems generallyrequire a great deal of time, effort, and knowledge forprogramming and debugging.
Home RF• was initiated in 1998 and has similar goals toBluetooth for WPAN.• Its goal is shared data/voice transmission.• It interfaces with the Internet as well as the PublicSwitched Telephone Network.• It uses the 2.4 GHz band and has a range of 50 m,suitable for home and yard.• A maximum of 127 nodes can be accommodated ina single network.
GSM Vs CDMA• Code Division Multiple Access, thereare many devices which use the samespread spectrum (hence multipleaccess).• There is one physical channel and aspecial code for every device in thecoverage network.• For example: There is a street onwhich many buses ply. Obviously, thebus will have many commuters, andthey will have to buy the tickets totravel on the bus. In CDMA, thecommuter is like your mobile phone,the tickets are your codes, the bus isa multiplexed carrier signal, and thestreet is the spread spectrum.• GSM is a cellular technology, that is,the entire coverage area is dividedinto various hexagonal shaped cells(hence the popular name cellphones).• Every cell has a correspondingnetwork tower, which serves themobile phones in that cellular area.
GSM Vs CDMAComparison GSM CDMA RatioCall Quality More echo, call dropping,voice distortion is moreEchos, call dropping, voicedistortion is less0:1Carriers Users can change theircarriersBased on handset change 1:1Network 112 for emergency Nothing 2:2Worldwide International roaming canbe providedLack of Intl roaming 3:2Battery Life Less battery More Battery 4:2Coverage Everywhere Everywhere 5:3Speed Into 3G Into 3G 6:4Penetration Good penetration Good penetration in the recentdays7:5
Mobile Adhoc Networks (MANETs)• A mobile ad-hoc network (MANET) is a self-configuringinfrastructure less network of mobile devices connectedby wireless links.• Each device in a MANET is free to move independently in anydirection, and will therefore change its links to other devicesfrequently.• The growth of laptops and 802.11/Wi-Fi wireless networking havemade MANETs a popular research topic since the mid 1990s.• Different protocols are then evaluated based on measure such asthe packet drop rate, the overhead introduced by the routingprotocol, end-to-end packet delays, network throughput etc.
Vehicular Adhoc Networks (VANETs)• A Vehicular Ad-Hoc Network, or VANET is atechnology that uses moving cars as nodes ina network to create a mobile network.• VANET turns every participating car into awireless router or node, allowing carsapproximately 100 to 300 metres of eachother to connect and, in turn, create anetwork with a wide range
Vehicular Adhoc Networks (VANETs)• As cars fall out of the signal range and dropout of the network, other cars can join in,connecting vehicles to one another so that amobile Internet is created.• It is estimated that the first systems that willintegrate this technology are police and firevehicles to communicate with each other forsafety purposes.
Intelligent Vehicular Adhoc Networks(VANETs)• Intelligent vehicular ad-hoc networks(InVANETs) use WiFi IEEE 802.11p(WAVEstandard)and WiMAX IEEE 802.16 for easy andeffective communication between vehicleswith dynamic mobility.• Effective measures such as mediacommunication between vehicles can beenabled as well methods to track automotivevehicles
Intelligent Vehicular Adhoc Networks(VANETs)• Vehicles are enabled to communicate amongthemselves (vehicle-to-vehicle, V2V) and viaroadside access points (vehicle-to-roadside,V2R).• Currently there is ongoing research in the fieldof InVANETs for several scenarios. The maininterest is in applications for traffic scenarios,mobile phone systems, sensor networks andfuture combat systems
Wireless Sensor Networks (WSN)• Sensor networks contain large collection ofnodes which are autonomous in nature andhas short range communication. Sensor nodesare good for monitoring the animal habitat(movement) in forest, identifying the ripenedfruit among given set of fruits, objects in abuilding, etc.
Wireless Sensor Networks (WSN)• Energy is scarce resource, means once thebattery is drained, there may be situationwhere the battery may not be replaced (Eg.dense forests, sea, ocean, etc• Also sometimes the nodes will be thrown in tothe sea or ocean for identifying fishavailability.• Sometimes they are short lived. They give datafor sometime and after that they die.
Adhoc Vs Sensor Networks• Sensor nodes are densely deployed and prone to failuresfrequently.• Number of sensor nodes are huge when compared withthe adhoc nodes.• Sensor network topology changes frequently.• Sensor nodes uses broadcasting whereas the adhoc nodesuses point to point communication• Sensor nodes are limited in memory and power• it has limited computation (simple operations)• Above all, All sensor nodes have a common goal (for aparticular achievement)