Connectivity Aspects

Role of communication architectures in pervasiveness
•The pervasive computing system needs at least two basic elements to be pervading everywhere they are required to pervade:
O Computing elements to take care of computational needs; and,
O Communication elements to interconnect these computing elements either through wires or wirelessly (with / without mobility).

•From the end user‟s perspective and in many a practical situations, the wireless communication based mobile computing is becoming increasingly important.
•From the back-end systems‟ viewpoint, however, due to its sheer traffic volume, low error rates, better noise immunity and low cost, the wire line communication based computing still remains an attractive option. •Therefore, hybrid architectures will possibly continue to exist even though end users may not be even aware of it. Identifying multi-technology mobile communication architectures of relevance
•Several generations
•Gradual enhancements
•Coexistence & transition


Generations of Wireless Communication Networking Standards
•First Generation Global Mobile Radio standard : 1G 
O Only voice, No data
•Second Generation Global Mobile Radio standard : 2G 
oGSM:9.6 Kbps <circuit switched voice / data>
O Enhanced Second Generation Global Mobile Radio standard : 2.5G§GSM-GPRS <combination of circuit and packet switched voice / data>
§GPRS-136: <100Kbps <packet switched>
•Third Generation Global Mobile Radio standard: 3G
 oCDMA2000,=< 2Mbps <packet switched voice / data>
 •Fourth Generation Global Mobile Radio standard : 4G (near future)
o 20-40 Mbps <packet switched voice / data>