For Push-To-Talk (PTT) system based on Public Mobile Data Network (PMDN), the end-to-end time delay is the key aspect of the user's experience. The Push-Over-Cellular (POC) scheme defined by Open Mobile Alliance (...For Push-To-Talk (PTT) system based on Public Mobile Data Network (PMDN), the end-to-end time delay is the key aspect of the user's experience. The Push-Over-Cellular (POC) scheme defined by Open Mobile Alliance (OMA) is based on the VoIP phone model and use SIP protocol as the call control scheme. The call setup time delay in SIP may reach to several seconds, which is unac-ceptable for the PTT service. In this paper, we provide a new call control scheme for PTT system based on PLMN network. By combining the apriority knowledge of PTT call model and the priority control scheme, we encapsulate the signaling message and the voice data into a same data packet, when the user push the button, the voice and the call control signaling are sent to the server at the same time. So the long time delay of call setup procedure of POC scheme can be eliminate. The end-to-end call delay can be decreased significantly. The experiment result based on the commercial CDMA2000 1X network of China Unicom shows that the call delay can be decreased to 600 ms, which approach to the traditional trunk communication system's requirement.展开更多
“长江，长江，我是黄河，收到请回复。”……这个耳熟能详的电影对白如果随时随刻在我们身边出现，大家一定会觉得是对讲机发烧友们的恶作剧：再如果某天看到某人打开手机的第一件事不是拨打电话，而是打开了类似QQ中常用的群组功能，...“长江，长江，我是黄河，收到请回复。”……这个耳熟能详的电影对白如果随时随刻在我们身边出现，大家一定会觉得是对讲机发烧友们的恶作剧：再如果某天看到某人打开手机的第一件事不是拨打电话，而是打开了类似QQ中常用的群组功能，查看着自己“好友们”的在线情况，并肆无忌惮地和在线的好友们瞎扯起来的话，千万不要认为这是运营商又在搞话费优惠活动，这一切完全是得益于一项为我们既熟悉但又陌生的技术——PTT（Pusn To Talk，简称PTT，意为“即按即说”）。展开更多
文摘For Push-To-Talk (PTT) system based on Public Mobile Data Network (PMDN), the end-to-end time delay is the key aspect of the user's experience. The Push-Over-Cellular (POC) scheme defined by Open Mobile Alliance (OMA) is based on the VoIP phone model and use SIP protocol as the call control scheme. The call setup time delay in SIP may reach to several seconds, which is unac-ceptable for the PTT service. In this paper, we provide a new call control scheme for PTT system based on PLMN network. By combining the apriority knowledge of PTT call model and the priority control scheme, we encapsulate the signaling message and the voice data into a same data packet, when the user push the button, the voice and the call control signaling are sent to the server at the same time. So the long time delay of call setup procedure of POC scheme can be eliminate. The end-to-end call delay can be decreased significantly. The experiment result based on the commercial CDMA2000 1X network of China Unicom shows that the call delay can be decreased to 600 ms, which approach to the traditional trunk communication system's requirement.
文摘“长江，长江，我是黄河，收到请回复。”……这个耳熟能详的电影对白如果随时随刻在我们身边出现，大家一定会觉得是对讲机发烧友们的恶作剧：再如果某天看到某人打开手机的第一件事不是拨打电话，而是打开了类似QQ中常用的群组功能，查看着自己“好友们”的在线情况，并肆无忌惮地和在线的好友们瞎扯起来的话，千万不要认为这是运营商又在搞话费优惠活动，这一切完全是得益于一项为我们既熟悉但又陌生的技术——PTT（Pusn To Talk，简称PTT，意为“即按即说”）。
