MSS MSS Fixed Network MSS MSS 1 6 2 i 5 3 4 New Call Arrival Y is the estimated load le accepted load la Compute fr la le N Generate Probability Pr Is Pr fr N Y Is a channel available Y Channel Assigned Call Blocked Ongoing Call Channel Release N Call Blocked G F D E MT2 B I A H Segments EF FG and FH are handoff probable segments MT1 C Handoff Region J Flow A Flow A Time a bandwidth bandwidth Flow B Flow B Time b GGSN IP Backbone UMTS CORE SGSN AP UTRAN AP Cell Phone WLAN terminal a APC AP RNC AP Node B Mobile Node AP Mobile Node b A call request arrival No it s a data call Voice call yes No it s a handoff call New Call Try Cellular yes No free bandwidth avail For voice in cellular No In double coverage yes No No No Try Cellular From cellular To WLAN yes yes New Call Try WLAN Bandwidth Avail In WLAN yes No yes In double coverage No yes No Bandwidth Avail In Cellular Bandwidth avail In WLAN Try WLAN yes yes No free bandwidth Avail in WLAN yes Accepted to Cellular Rejected No No Rejected Accepted to WLAN Accepted to Cellular Remain in Cellular Traffic Class Conversational Applications Delay Voice one to one video Stringent Broadcast Audio Video Constrained Jitter Low Guaranteed Losses Bit rate Stringent Yes Constrained Yes Real Time Streaming Real Time Interactive Web Database Games Best Effort Background Best Effort Emails File Transfer Loose Yes Yes Traffic class Fundamental characteristics Conversational class Streaming class conversational RT streaming RT Preserve time relation variation between information entities of the stream Preserve time relation variation between information entities of the stream Interactive class Background Interactive best effort Background best effort Destination is not Request response expecting the data within a certain time pattern Preserve payload content Conversational pattern stringent and low delay Example of the application voice Preserve payload content streaming video Web browsing Background download of emails CAC GGSN PPM MMM SGSN SGSN Core networks Access networks Monitor RNC RNC RNC Node B Node B Roaming In AP Roaming out Node B UMTS domain WLAN domain WLAN domain WLAN domain Cdma2000 domain Other domains Ethernet ad hoc Networks sensor networks WMANs etc DiffServ Internet backbone GSM GPRS domain WLAN domain Gateway Router Cellular Domain WLAN domain
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