17-01-2013, 10:12 AM
SEAMLESS WIRELESS CONNECTIVITY FOR MULTIMEDIA SERVICES IN HIGH SPEED TRAINS
Utilization of railway trajectory.ppt (Size: 1.53 MB / Downloads: 50)
INTRODUCTION
Mobile handheld changed mobile networking
High speed trains becoming popular means of communication
Multimedia communication becoming essential
Access become critical demand
Demand for higher data rates &capacity
Expensive to build special network
General networking adopted
LTE
Standard for wireless data communications technology for high speed data
Evolution of GSM/UMTS standards
Goal- increase capacity & speed
Support packet switched networks
Provide seamless internet protocol connectivity between user equipment(UE) & packet data network(PDN)
E-UTRAN architecture
FEATURES
High speed data rate
Downlink peak rate-300Mbps
Uplink peak rate-75Mbps
Data transfer latency –less than 5ms
Ability to manage fast moving mobiles
Carrier bandwidths-1.4MHz to 20MHz
seamless handover for voice &data
Support various cell sizes
Improve capacity &coverage
FEMTOCELL
Network infrastructure for micro-ization of cellular networks is very expensive
Solution user deployed base stations (femtocells)
Users purchase and install themselves a small low-power BS at their apartment/office
Small cellular base station designed for limited coverage
Used to extend wireless service coverage
Cell radius-20m to 50m
Femtocell networks: technical aspects
Femtocell AP:
Low transmitted power
Low range
Indoors
IP backhaul connection to the core network through the broadband access the user already has at home
To ensure widely deployment (users have to buy it)
Much simpler than a “regular” cellular BS
Not synchronized with the rest of the network
Already being manufactured by some vendors
ADVANTAGES
Reduced call costs
Increased call capacity
Licensed spectrum
Special services
Continued use of current handset
Multiple users/lines
Improved indoor coverage
Applicable to all standards
CONCLUSION
Utilization of railway trajectory
Infrastructure with femtocell and cell array
Predictive handover & Scheduling algorithm
Interference mitigation techniques
Achieves
High latency
Lower delay
High throughput
Seamless handover