ABSTRAKSI: Worldwide Interoperability for Microwave Access (WiMAX) dan Wideband Code Division Multiple Acces/Universal Mobile Telecomunication System (WCDMA/UMTS) yang merupakan generasi baru dari Global System Mobile (GSM) menjadi salah satu alternatif dalam menyediakan layanan Broadband Wireless Access (BWA) untuk user. WiMAX memiliki data rate besar namun kurang mendukung mobilitas dan juga penggunaan jaringan WiMax yang masih dibilang jarang sehingga membatasi coverage layanan dari provider penyelenggara WiMAX, WCDMA/UMTS mendukung mobilitas user tapi dengan data rate sedang namun jaringan sudah tersedia hampir di seluruh daerah. Melihat hal ini muncullah ide untuk mengkombinasikan kedua teknologi tersebut sehingga kelemahan keduanya bisa tertutupi. Saat ini teknologi Mobile IP (MIP) dinilai mampu untuk mewujudkan hal ini. MIP memberikan kemampuan kepada user untuk bergerak dan berganti IP Address setiap saat tanpa memutus/me-restart komunikasi data yang sedang terjadi.
Pemodelan penelitian pada Tugas Akhir ini difokuskan pada arah downlink dimana Corespondent Node (CN) mengirimkan paket data kepada sebuah mobile node (MN) yang berada di jaringan WCDMA/UMTS (home network), namun pada saat proses pengiriman data tersebut mobile node melakukan perpindahan titik sambung ke sebuah jaringan mobile WiMAX (foreign network). Evaluasi dan analisa sistem interworking ini dilakukan secara protokol, dimana akan dianalisa jalannya paket data pada layer-layer protokol jaringan WCDMA/UMTS-mobile WiMAX serta MIPv6 process pada saat menangani komunikasi data.
Hasil analisa dan evaluasi sistem interworking menunjukan bahwa komunikasi data pada saat awal komunikasi belum maksimal, hal ini dikarenakan sistem tersebut masih harus melakukan CoA addressing, Binding Update-Acknowledge (BU-BA) Mobile Node (MN) dengan Home Agent (HA), serta BU-BA MN dengan CN. Sistem interworking ini bekerja maksimal saat CN sudah mampu untuk berhubungan langsung dengan CoA MN tanpa intercept HA, yaitu setelah BU-BA MN dengan CN. RADIUS berperan dalam proses Authorization, Authentication, Accounting (AAA) antara MN dengan mobile WiMAX dan WCDMA/UMTS network. MIPv6 routing header mengganti destination address pada header IPv6 yaitu MN COA dengan HoA pada saat paket tersebut sampai di MN CoA sehingga seolah-olah tidak ada pergantian IP address.
Kata Kunci : Mobile WiMAX, MIP, RADIUS, MIPv6 routing header, Roaming IntersystemABSTRACT: Worldwide Interoperability for Microwave Access (WiMAX) and Wideband Code Division Multiple Access/Universal Mobile Telecommunication System (WCDMA/UMTS) which is the new genertaion of GSM (Global System for Mobile communication) become an alternative in providing the future Broadband Wireless Access (BWA). WiMAX has very high datarate but it is quitely limited in Access Network because of the infrastructure of WiMAX itself is still rarely, so it is only support for user mobility for small coverage area. In the other hand WCDMA/UMTS has high enough datarate and also WCDMA/UMTS access network arsitecture is provided in almost of every angle of region so it is highly support for user mobility.
Base of those reasons above, there were an idea to combine the two technologies so they can takes the benefit of each other. WiMAX can support the higher datarate of WCDMA/UMTS and WCDMA/UMTS can allow WiMAX user to have higher mobility support. Now, MIP is the most capable technology to realize this 2 planning. MIP allow user to change the IP address or point of attachment without restarting the communication which is go on.
This project is use WiMAX-WCDMA/UMTS roaming scenario that HA (Home Agent) as the MIP server is provided by WCDMA/UMTS network as a home network (network which is user do registration and get IP address for the first time). The research methode is in downlink direction, where CN (Correspondent Node) sending packet data to MN (Mobile Node) in UMTS network, MN makes a handover toward mobile WiMAX network. The evaluation and analyzation of the scenario is done by protocol description, where as could be explained the packet transportation on the layer-layer protocol of WCDMA/UMTS and mobile WiMAX network. It is also explained the MIPv6 process when handled the data communication and handover.
The evaluation of intersystem roaming shows that in the beginning of communication is not optimal, this is because the MN must do CoA (Care of Address) addressing Binding Update-Acknowledge with the HA and BU-BA with the CN. The roaming will working optimal when the CN is able to communicate directly with the MN in the foreign network without interception of HA. That is after MN do BU-BA with the CN.
RADIUS protocol take control on Authentication, Authorization and Accounting process between WiMAX’s and UMTS’s AAA server. MIPv6 header change the destination address on header IPv6 that is MN CoA with MN HoA when the packet is arrive to MN CoA, so the IP address changing is hidden from the upper layer.
Keyword: Mobile WiMAX, WCDMA/UMTS, MIP, RADIUS, MIPv6 routing header, Roaming