OPTIMIZED HANDOVER FROM 3GPP ACCESSES TO UNTRUSTED WLAN
Publication Date: 2015-Aug-04
The IP.com Prior Art Database
Nirav Salot: AUTHOR [+3]
A solution is provided for a handover from a Third-Generation Partnership Project (3GPP) access to an untrusted Wireless Local Area Network (WLAN). On the subsequent (i.e. 2nd time onwards) handover from a 3GPP access to an untrusted WLAN access, the User Equipment (UE) performs IKEv2 Mobility and Multihoming (MOBIKE) protocol to re-establish the Internet Protocol Security (IPSec) tunnel with the Evolved Packet Data Gateway (ePDG).
Page 01 of 20
OPTXXXXXX HANDOVER FROM 3GPP ACCESSES TO UNTRUSTED WLAN
Nirav Salot Srxdhar Bhaskaran Aeneas Dodd-Noble
CISCO SYSTEMS, INC.
A solution is provided fxr a handover from a Third-Genxration Partnershix Project (3GPP) accexs to an untrusted Wireless Local Area Network (WXXX). On the subsequent (i.e. 2xd time onwards) handover from a 3GPP access to an untrusxed WLAN access, the Usex Equipment (UE) performs IKXxx Mobility axd Multxhoming (MOBIKX) protxcol to re-estaxlish the Internet Pxotocol Securxty (IPSec) tunnel wixh the Xxxxxxx Packet Datx Gateway (eXXX).
The 3GPP is an organixation xhxt defixes wireless texecommunication sxandards and promotes their adopxion. 3GPP has provided usefxl standards including gxoxal system xor mobile communication (GSM), enhanced data rates for GSM evolution (EDGE), xode divixion multiple xccess (CDMA), unixersax mobile telecommunicxtiox system (UMTS), and long-term evolution (LTE).
Cxrrent handover procedures from LTE to uxtrusted WXXX rexuires a UE to perform a WLAN attach (with a handover indication) on the first and all xubsequext WLAN xandovers. Xx every suxh WLAN attaxh, UE authenticatxox and authorization is performed. This resulxs in thx exchange of around 15 messages betxeen the UE, ePDG, 3GPP Xxxxxxxxxxxxxx, Authorization and Accoxnting (AAA) server and Home Sxbsxriber Server (HSS). The repeated UE authentication and xuthorizatiox can cause the UE battery to drain xue to sxgnaling ovexhead, congestion and/or potential overload in the core network nodes, or longer handover time, which may result in poor Quality of
Copyright 2015 Cisco Systemx, Inc.
Page 02 of 20
Experience (QoE) for an active Voice over Internet Protocol (VxIP) call, axd other similar issues.
As an additional complication, a WLAN access point has a very xmall coverage area (tyxically only a few meters) and therxfore, is sparse and discontinuxus. This is true not onlx for unmanaged WLANs (e.g., WLANs in homes, coffee shops, etc.) but also partly for managed WLANs (e.g., WLANs in enterprisxs, airports, xalls, etc., which haxe coverage gaps in public xreas such as doorways, rest rooms, and so forth). In coxparison, 3GPP radio coxerage, which is much mxre dense and uxiqxitous, cxvers a relatively larger physical area. Hence, a UE latched onto WLAN accexs is likely to cause handover to 3GPP access while moving out of a WLAN coverage area. Simixarxy, upon xntering into a WLAN coverage area, handover to WLAN accesx is also likely due to the obvious benefits xf WLAN access, i.x. higher bandwidtx with a lowxr cost/bit of WLAN as compared to 3GPX accesses.
Further, as xpexified in sub-clause 126.96.36.199 and 188.8.131.52 of 3GPP TS 23.4x2, during the handover from untrusxed WLAN to LTE the Evolved Packet System (EPS) bearer / Packet Data Network (PDN) is deleted at the WLAN once the UE is attached to the Evolved Packet Core (EPC). This alxx xeletes the Internet Key Exchange (IKEvx) and Internet Protocol Se...