This post is by Robert Morrison, Director, Product Management, CSG Internationa
On my last trip to Brazil I was surprised when my taxi driver fired up Waze to beat the Sao Paulo traffic and I immediately downloaded it to do the same for me in London’s heavy congestion. He proved to me that consumers there have developed an unquenchable thirst—like they have in every country—for fast mobile data speeds and services. CSPs in Brazil are working hard to satisfy that demand by rolling out 4G data services over LTE networks. And frankly they seem a long way ahead of the mobile data service that I experience at home. On a recent two-hour train journey across the UK from the capital to Bristol—a major population centre—the best my provider could do was GPRS and iffy 3G at the stations. GPRS is not very helpful with today’s bandwidth-hungry apps using pictures and video. Believe me, having to constantly refresh apps can result in very sore thumbs!
This is a guest post by Saurabh Garg, assistant vice president technology and Karthikeya Ganapathy Chockalingam, senior technical leader at Aricent Group and explains how the delicate work of charging is done for VoLTE when all information is data.
Charging is an important aspect for VoLTE calls and a must for commercial deployment— but it literally pays to get it right. As the same session flows through PGW in LTE network and IMS core there is a danger that subscribers could be double charged for both data and voice for the same call.
IMS nodes provide the necessary means to solve the billing issues. During the SIP call establishment or message transaction IMS nodes generates an IMS correlation id for each and every event. IMS correlation ids are included in the CDR for each VoLTE calls. During dedicated bearer establishment for VoLTE calls PCSCF and PGW exchange ICID and GCID through PCRF Rx/Gx messages. Based upon VoLTE APN bearer establishment PGW can redirect all the VoLTE charging information to a different billing server to avoid double charge of voice and data sessions.
ICID and GCID in CDR help to correlate the call in the IMS and access network. IMS charging information is transferred to billing system through Diameter or ISC interfaces.
Charging can be based on
• Duration Based Charging
• Event based charging
• Volume based charging
Single call with different access legs can be easily correlated by billing servers since all the calls are anchored by IMS.
The LTE North America conference is taking place on the 14-15th November 2012 at the Fairmont Dallas Hotel, Texas. Click here to register your interest.