摘要:
This invention provides a system and method for enhancing point coordination function in wireless LANs. A contention procedure is introduced into PCF in this invention. When the point coordinator (PC) polls the mobile terminal who has no frame to send, the terminal does not respond to the CF-Poll from PC, and will adjust its NAV and set it to a special value that is defined as SPIFS. When data is ready on this mobile terminal, the terminal can contend for accessing the medium. If it detects the medium to be idle for SPIFS period during the CFP, then the mobile terminal gains the control of medium and starts to send the ready data. So this mobile terminal can have another opportunity to gain the control of medium during this CFP instead of next CFP, and this can decrease the transmission delay.
摘要:
The present invention takes the advantage of the WLAN resources in hotspots for voice and data connections and enables seamless handover between WWAN and WLAN and vice versa. This allows two users in the hotspots to communicate with each other by making a voice over IP (VoIP) or video call, thus achieving cost savings for the end users and WWAN resources savings for the wireless operators. According to one embodiment of the invention, a mobile terminal has wireless wide area network (WWAN) and wireless local area network (WLAN) interfaces. The mobile terminal via a WWAN. If a WLAN is present, the mobile terminal sends a handover request together with its network address to the called mobile terminal, using a short message service (SMS) technique or a watermarking technique, for initiating a WLAN call with the called mobile terminal via a WLAN. After the WLAN call is established with the called mobile terminal, the mobile terminal releases the WWAN call.
摘要:
The present invention takes the advantage of the WLAN resources in hotspots for voice and data connections and enables seamless handover between WWAN and WLAN and vice versa. This allows two users in the hotspots to communicate with each other by making a voice over IP (VoIP) or video call, thus achieving cost savings for the end users and WWAN resources savings for the wireless operators. According to one embodiment of the invention, a mobile terminal has wireless wide area network (WWAN) and wireless local area network (WLAN) interfaces. The mobile terminal via a WWAN. If a WLAN is present, the mobile terminal sends a handover request together with its network address to the called mobile terminal, using a short message service (SMS) technique or a watermarking technique, for initiating a WLAN call with the called mobile terminal via a WLAN. After the WLAN call is established with the called mobile terminal, the mobile terminal releases the WWAN call.