LTE (News - Alert) is starting to no longer be the selling point for mobile operators as it becomes the standard IP mobile core. There are close to 300 commercial LTE networks now in more than 100 countries, according to the Global Mobile Suppliers Association (GSMA (News - Alert)), and nearly 500 network operators have announced plans for LTE deployments.
Having LTE is no longer the competitive edge it once was for an operator, and those that fail to have reliable LTE will find their subscribers bolting to other providers in a hurry.
Ensuring reliable LTE requires having a healthy evolved packet core (EPC), since it is at the heart of LTE traffic. Ensuring that the EPC is healthy requires keeping a few challenges in mind.
First, LTE signaling storms need to be accounted for.
“It’s important that mobile operators design the EPC to prevent equipment or link failures from propagating to other nodes in the network and triggering additional issues such as LTE signaling storms and overload conditions that further disrupt user services,” noted a TechZine posting by David Nowoswiat , Sr. Product and Solutions Marketing Manager, Alcatel-Lucent (News - Alert) entitled appropriately, “LTE Signaling: Prevent Attach Storms”.
Restoration for idle users also needs to be handled at the EPC. Before 3GPP 10.5, if an LTE subscriber in idle state was connected to the network and assigned to an MME/S4-SGSN that subsequently failed or restarted, that subscriber might not receive any services for an extended period of time.
Restoration for active users also is an issue, since the user’s session will immediately drop and the service will terminate in the case of MME/S40SGSN failure.
As a recent white paper on LTE subscriber service restoration by Alcatel-Lucent detailed, one solution to these problems is having a session restoration server that can store and maintains a database of key parameters of the UE subscriber context data that can be immediately retrieved by the remaining MMEs in the pool in the case of failure.
Alcatel-Lucent’s 9471 Wireless Mobility Manager can serve this function. It can deliver service reliability in case of a MME or SGW failure, achieve restoration of user data, and eliminate the need to reattach to the network.
It also can deliver dependability by preventing failure of network-originated IMS services, and prevent a failed MME from escalating into an LTE signaling attach storm.
LTE is no longer the future—it is the present. Operators now need to ensure their EPC is up to the task.
Edited by Peter Bernstein