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EU Project BRAIN Handover in the IP-based Radio Access Network Arndt Kadelka Aachen University of Technology, ComNets, Germany. Mobility Concept investigated in European BRAIN Project Serving Global and Local IP Mobility Performance of HiperLAN/2 Handover Procedures
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EU Project BRAINHandover in the IP-based Radio Access NetworkArndt KadelkaAachen University of Technology, ComNets, Germany Mobility Concept investigated in European BRAIN Project Serving Global and Local IP Mobility Performance of HiperLAN/2 Handover Procedures Integration of HiperLAN/2 Mobility and Local IP Mobility
Other Networks IP WAN IP Backbone Supports: - QoS for realtime services- Multicast- Handover SGSN UTRAN Node B Node B RNC Roaming Vertical Handover BRAIN Radio Cells Horizontal Handover BRAIN Radio Cells BRAIN System Concept using HiperLAN/2-based Access
Serving Local and Global Mobility • Hierarchical Mobility • Mobility across Wireless Access Networks served by rather slow Mobile IP • Mobility within Wireless Access Network served by fast protocols, e.g., Cellular IP, HAWAII
Local Handover within Access Network – Cellular IP • Route update by Uplink IP packets sent hop-by-hop to Gateway Router
HiperLAN/2-based Radio Access • Operates in the license exempt spectrum in5-6 GHz band • Radio cells up to 200 m • 25 Mbit/s typical data rate • Radio access can be adapted to various networksBRAIN: IP Conv. Layer
Actions to Perform a handover In H/2 fast handover decision and execution is performed by the MTs: • Scanning for alternative channel, i.e., served by different APT • MT indicates absence to serving AP, AP stops data transmission • MT performs measurements on alternative channel(s) • MT may return to serving AP or perform a handover • Handover decision • MT decides to perform a handover based on RSSI and PER measurements • Hysteresis to avoid ping-pong-effects • Handover execution • MT may indicate handover intention to serving AP • MT initiates handover by Handover_Request to target APT, i.e, forward handover • Re-establishment of link layer communication
Packet Transmission Delay owing to Scanning Downlink Transmission Uplink Transmission Amount of data effected by scanning:
Handover within H/2 Radio Access Network • Radio HO performed within DLC • IP layer not involved • Inter-Subnet Network Handover involves also IP layer • Route update of IP routing tables
Serving Local Mobility with H/2 • Changing point of attachment to the network • Re-establishment of link layer communication via the air interface • Re-registration to the IP network • Authentication • Maintaining on-going DLC connections • Integration with IP mobility via IP CL
Slow Network Handover Procedure • Interworking with Cellular IP • IP CL triggers route update packet • Loss of IP packets received at APold before route update execution
Fast Network Handover with Backbone Signaling • Information about on-going DLC connections retrieved via backbone • Packets routed to APold are tunneled to APnew • DLC address of APold is indicated during HO_Association • AP has to maintain address mapping table • APold DLC IP address
Making use of Slow and Fast Network Handover • To make best use of Fast Network Handover procedure IP address of old AP must be known • Mapping table may be set up • manually, by operation and maintenance procedures • administration effort • not flexible • dynamically, by following procedure • AP selects handover procedure to be executed, i.e., Slow or Fast Network Handover • MT performing 1st Handover from APold to Apnew carries out Slow Network Handover and provides DLC address (during HO_Association) and IP address of Apold (via Info_Transfer) • Stores DLC/IP-address mapping • Subsequent handovers from this APold are performed according Fast Handover procedure
Conclusion • H/2 defines handover procedures to serve local mobility • For H/2 mobility integration with IP local mobility interworking functions are investigated and defined for the new IP CL • To perform network handover involving the IP network almost as fast as radio handover address mapping table has to be maintained in IPCL • Procedure defined to set up the mapping table dynamically • Work will be continued in follow-up project MIND • Specification of IPCL and contribution to ETSI/BRAN • Mobility integration with UMTS (Vertical Handover)