4g To3g Handover

eUTRAN to UTRAN Iu mode Inter RAT RA T handover h andover General information Pre-conditions: 

The UE is in ECM-CONNECTED state (E-UTRAN mode).

If emerenc! "earer ser#ices are onoin for an UE$ hando#er to the taret RNC is %erformed inde%endent of the &ando#er Restriction 'ist. The N chec*s$ as %art of the Ro+tin Area U%date in the e,ec+tion %hase$ if the hando#er is to a restricted area and if so N deacti#ate the non-emerenc! PDP conte,t.

Preparation phase

i. . E-UTRAN to UTRAN I+ mode Inter RAT RAT &O %re%aration %hase. Inter-RAT T hando#er to the taret access Step 1. The so+rce eNode/ decides to initiate an Inter-RA net0or*$ UTRAN I+ mode. At mode. At this %oint "oth +%1in* and do0n1in* +ser data is transmitted #ia the fo11o0in: /earer(s) "et0een UE and so+rce eNode/$ TP t+nne1(s) "et0een so+rce eNode/$ er#in 2 and PDN 2. 2.

If the UE has an onoin emerenc! "earer ser#ice the so+rce eNode/ sha11 not initiate P hando#er to a UTRAN ce11 that is not IM #oice ca%a"1e. te% 3. The so+rce eNode/ sends a &ando#er Re4+ired (AP Ca+se$ Taret RNC Identifier$ C ID$ C access mode$ o+rce eNode/ Identifier$ o+rce to Taret Trans%arent Container) messae to the so+rce MME to re4+est the CN to esta"1ish reso+rces in the taret RNC$ taret N and the er#in 2. The "earers that 0i11 "e s+"5ect to data for0ardin (if an!) are identified "! the taret N in a 1ater ste% (see step 7 "e1o0). 2hen the taret ce11 is a C ce11 or a h!"rid ce11$ the so+rce eNode/ sha11 inc1+de the C ID of the taret ce11. If the taret ce11 is a h!"rid ce11$ the C access mode sha11 "e indicated. Step 3. The so+rce MME determines from the 6Taret RNC Identifier6 IE that the t!%e of hando#er is IRAT &ando#er to UTRAN I+ mode. The o+rce MME initiates the &ando#er reso+rce a11ocation %roced+re "! sendin a or0ard Re1ocation Re4+est (IMI$ Taret Identification$ C ID$ C Mem"ershi% Indication$ MM Conte,t$ PDN Connections$ MME T+nne1 End%oint Identifier for Contro1 P1ane$ MME Address for Contro1 %1ane$ o+rce to Taret Trans%arent Container$ RAN Ca+se$ M Info Chane Re%ortin Action (if a#ai1a"1e)$ C Information Re%ortin Action (if a#ai1a"1e)$ UE Time 7one$ IR +%%orted) messae to the taret N. The information IR +%%orted is indicated if the so+rce MME and associated er#in 2 are ca%a"1e to acti#ate IR for the UE. 2hen IR is acti#ated the messae sho+1d  "e sent to the N that maintains IR for the UE 0hen this N is ser#in the taret identified "! the Taret Identification. This messae inc1+des a11 PDN Connections acti#e in the so+rce s!stem and for each PDN Connection inc1+des the associated APN$ the address and the +%1in* T+nne1 end%oint %arameters of the er#in 2 for contro1 %1ane$ and a 1ist of EP /earer  Conte,ts. RAN Ca+se indicates the AP Ca+se as recei#ed from so+rce eNode/. The so+rce MME sha11 %erform access contro1 "! che c*in the UE6s C s+"scri%tion 0hen C ID is %ro#ided "! the so+rce eNode/. If there is no s+"scri%tion data for this C ID or the C s+"scri%tion is e,%ired$ and the taret ce11 is a C ce11$ the so+rce MME sha11 re5ect the hando#er 0ith an a%%ro%riate ca+se. The so+rce MME inc1+des the C ID in the or0ard Re1ocation Re4+est 0hen the taret ce11 is a C ce11 or h!"rid ce11. 2hen the taret ce11 is a h!"rid ce11$ the C Mem"ershi% Indication indicatin 0hether the UE is a C mem"er sha11 "e inc1+ded in the or0ard Re1ocation Re4+est messae. The taret N ma%s the EP "earers to P DP conte,ts -to- and ma%s the EP /earer 8o  %arameter #a1+es of an EP "earer to the Re1ease 99 8o %arameter #a1+es of a "earer conte,t. Prioritiation of PDP Conte,ts is %erformed "! the taret core net0or* node$ i.e. taret N. The MM conte,t contains sec+rit! re1ated information$ e.. s+%% orted ci%herin a1orithms The taret N sha11 determine the Ma,im+m APN restriction "ased on the APN Restriction of  each "earer conte,t in the or0ard Re1ocation Re4+est$ and sha11 s+"se4+ent1! store the ne0 Ma,im+m APN restriction #a1+e. Step 4. The taret N determines if the er#in 2 is to "e re1ocated$ e. .$ d+e to P'MN chane. If the er#in 2 is to "e re1ocated$ the taret N se1ects the taret er#in 2$ and sends a Create ession Re4+est messae (IMI$ N T+nne1 End%oint Identifier for Contro1 P1ane$ N Address for Contro1 %1ane$ PDN 2 address(es) for +ser %1ane$ PDN 2 U' TEID(s) for +ser %1ane$ PDN 2 address(es) for contro1 %1ane$ and PDN 2 TEID(s) for contro1 %1ane$ the Protoco1 T!%e o#er ;