[TICTOC] FW: Adding the Femto Synchronization requirments in requirement document

Sent: Wednesday, August 26, 2009 9:50 AM

Subject: [TICTOC] Adding the Femto Synchronization requirments in requirement document

Dear All

As the agreement in IETF75# meeting, we decide to add the femto synchronization requirements in requirement document. After checking the requirement document, i think, the best way is to add a new section as following:

3.2.1 Cellular Backhauling of Femtocells

Femtocell application may use a portion of the public and private network infrastructure to provide connectivity and backhaul service between the femtocell device and gateway. The use of a public network facility implies that some level of network security is necessary, as compared to the scenarios presented in Section 3.1.1.x which assumed that the connectivity and backhaul service is done over a private network (eg., see Note (2)), typically for macrocell application. In addition the number of femtocell devices can easily extend to hundreds of thousands, much higher than the number of macrocells. The following requirements should be considered for femtocell deployments:

The use of IPSec links in the public network could degrade the transport of synchronization message and its performance. In order to reduce the impact to synchronization when traversing secured links, it is possible to leave some of the synchronization message unprotected. Caution should take place on the use of IPSec and synchronization performance
Synchronization messages traversing Network Address Translation (NAT) functions need to be considered in order to guarantee proper connectivity between a Clock Server and the femtocell device
Scalability aspects (large number of femtocells), bandwidth consumption of synchronization messages and the placement of clock servers are to be considered as the network architecture is developed.

Please give your comments on these words, Thanks

Best Regards

Rock