1 M o b i l i t y m a n a g e m e n t P i o t r P a c y n a 1
IP mobility management Piotr Pacyna AGH University of Science and Technology Department of Telecommunications Krakow 2018. 2
Cel wykładu Prezentacja metod wsparcia mobilności przewidzianych do stosowania w systemach 3G oraz 4G w świetle standardów 3GPP. Potrzeby i wyzwania w zakresie obsługi mobilności. Protokoły wsparcia mobilności zapewniające swobodną komunikację urządzeń ruchomych w warunkach częstych przełączeń. Architektura systemu 3PP SAE/LTE. Model wsparcia mobilności. 3
Cellular systems and Internet. Convergence IPv4 2G 3G IPv6-based network with mobility and security IPv6 SAE/LTE 2000 2010 2020 4
Potrzeba wsparcia mobilności IP Konwergencja systemów trwa. Cel: All IP system Protokół IPv6 nie wspiera częstych zmian punktu przyłączenia do sieci. Mobile IPv6 nie zapewnia należytej jakości obsługi ze względu na długi czas przełączenia (IP handoff latency) 5
Architectural challenges Packet switched system vs. packet switched. Conceptual separation of layers in IP. Lack of clear separation of data-plane and controlplane in IP. Connectionless, unreliable datagram service. Security never considered seriously (in the arch.) Host mobility never considered (in the arch.). IP-based mobility with fast handovers is difficult. Convergence of cellular systems and the Internet is progressing 6
Host-based mobility management - Mobile IPv6 Piotr Pacyna AGH University of Science and Technology Department of Telecommunications Krakow 2018. 7
Challenge #1 in IP-based mobility: Continuous reachability Home network How to reach MN??? CN MN Foreign network Use two IP addresses: address representing node identity and address representing node location (locator-identifier split) How to store address binding? How to update the binding? MN 8
Challenge #2 in IP-based mobility: Handover latency introduced by IP layer Link layer handover IP layer handover 9
Challenge #3: Technology heterogeneity Rozwiązanie winno być uniwersalne - niezależne od techniki transmisyjnej Internet IPv6 Operator Access router Access router Access router Access router Access router Access router 802.11 TD-CDMA TD-CDMA TD-CDMA 802.11 802.11 TD-WCDMA intradomain TD-WCDMA interdomain TD-WCDMA to 802.11 intradomain 802.11 to 802.11 interdomain 802.11 to 802.11 intradomain Mobile Terminal Access router 802.11 to Ethernet intradomain 10
Challenge #4: Operator requirements Rozwiązanie winno być uniwersalne - niezależne od techniki transmisyjnej Internet IPv6 Operator A (Domain A) Operator B (Domain B) Operator C (Domain C) Access router Access router Access router Access router Access router Access router 802.11 TD-CDMA TD-CDMA TD-CDMA 802.11 802.11 TD-WCDMA intradomain TD-WCDMA interdomain TD-WCDMA to 802.11 intradomain 802.11 to 802.11 interdomain 802.11 to 802.11 intradomain Mobile Terminal Access router 802.11 to Ethernet intradomain 11
Requirements for smart mobility management (handoff) scheme Compatibility: Mobility management solution must fit in the service model in cellular systems. Latency: the time required to complete the handoff should be appropriate for the rate of mobility of the mobile terminal, and the QoS requirements applications. Ubiquity: the handoff procedure should support handoffs within the same BS, between different base stations in the same and in different networks (hard-, soft- and softer handovers). Scalability: mobility control traffic (incl. handover management) and the processing overheads must not load the system. Performance: low call blocking probability; fast recovery Quality of service: should be sustained during and after handover. Efficiency: handoff should result in improved efficiency (of traffic load, reduced interference, energy consumption). 12
MIPv6 an example 13
14 Mobile IPv6 (1) Mobile Terminal leaves the Home Network and enters the Visited Network. Source: Moby Dick Project Deliverable D0101
Mobile IPv6 (2) By means of auto-configuration Mobile Terminal aquires IPv6 address in the visited network and uses it as a care-of address. Source: Moby Dick Project Deliverable D0101 15
Mobile IPv6 (3) Next, Mobile Terminal notifies Home Agent about its current care-of address and its current location (address of visited newtork). Source: Moby Dick Project Deliverable D0101 16
Mobile IPv6 (4) Home Agent registers care-of address of a Mobile Terminal and acknowledges sucessful registration. From now onwards, the Home Agent can forward traffic to Mobile Terminal while it is in foreign networks. Source : Moby Dick Project Deliverable D0101 17
Mobile IPv6 (5) Correspondent Node sends data packets to Mobile Terminal to the Home Network. Home Agent intercepts the packets. Source: Moby Dick Project Deliverable D010 18
Mobile IPv6 (6) Home Agent forwards data packets to care-of address of a Mobile with IPv6 in IPv6 encapsulation. Source : Moby Dick Project Deliverable D0101 19
Mobile IPv6 (7a) Mobile Terminal responds to the Correspondent Node with triangle routing. Source : Moby Dick Project Deliverable D0101 20
Mobile IPv6 (7b) At the same time the Mobile Node sends Binding Update to Home Agent and to Corespondent Node. Correspondent Node creates a local binding of home address and care-of address of a Mobile Terminal in its binding cache. Source : Moby Dick Project Deliverable D0101 21
Complete handoff process in Mobile IPv6 1. Movement detection, network attach. IPv6 2. IP address configuration Mobile IPv6 3. Binding update 22
MIPv6 Handover Procedure MN PAR NAR HA CN Router Advertisement (New Network Prefixes) Router Advertisement Data Packet [CoA:CN]Data Router Advertisement Packets will be lost until registration Data Packet [CoA:CN]Data MDL Report Neighbor Solicitation Neighbor Solicitation Neighbor Solicitation Neighbor Solicitation Binding Update (New CoA) Binding Ack Return Routeability Procedure Data Packet [New CoA:CN]Data
Mobile IPv6 - distinct features 1. Support of MIPv6 is part of IPv6 standard. 2. Deep integration of mobility with IPv6. 3. Strong security protection for the signalling messages. 4. Use of supplementary protocols such as: IPSec, message authentication, public keys, PKI. 5. Reliability of the user-data communications and signalling eg. lifetime parameter for Binding Update message. 24
Network-based mobility management - Proxy Mobile IPv6 Piotr Pacyna AGH University of Science and Technology Department of Telecommunications Krakow 2018 25
Requirements for PMIPv6 A jeżeli urządzenie nie wspiera procedur obsługi mobilności? Mobilność może być obsługiwana przez sieć! 26
Objectives for PMIPv6 Provide network-based mobility management Support for hosts that do not use any mobility management protocol No participation of mobile node during mobility related signaling Support intra-domain handovers Reuse MIPv6 deployed infrastracture Avoid tunnelling overhead over the air Support the node within restricted and topologically localized fragment of the network (PMIPv6 domain) 27
Proxy Mobile IPv6 (PMIPv6) Router dostępowy Router dostępowy Router dostępowy 28
Proxy Mobile IPv6 (PMIPv6) MobileIPv6 Przyłączenie Uwierzytelnienie Autokonfiguracja adresu IPv6 Komunikacja bezprzewodowa Przyłączenie Uwierzytelnienie Autokonfiguracja adresu IPv6 Komunikacja bezprzewodowa Przyłączenie Uwierzytelnienie Autokonfiguracja adresu IPv6 Komunikacja bezprzewodowa 29
Proxy Mobile IPv6 (PMIPv6) Proxy Mobie IPv6 IPv6: 2001:0::1/64 Przyłączenie Uwierzytelnienie?? Autokonfiguracja adresu IP Obsługa mobilności IPv6: 20AA:111::/64 NO PROBLEM! 30
Proxy Mobile IPv6 (PMIPv6) IP: 2001:0::1/64 IP: 20AA:111::/64 Przyłączenie Uwierzytelnienie Autokonfiguracja adresu IP Obsługa mobilności Przyłączenie Uwierzytelnienie Autokonfiguracja adresu I Obsługa mobilności 31
Host-based mobility vs. network-based mobility HA HA Route update Route update AR AR MN Movement MN MN Movement MN Host-based mobility Network-based mobility 32
Proxy Mobile IP - mobility entities LMA functionality: LMA is the topological IP anchor point for the mobile node s home network prefix(es)(it advertises those prefixes) Responsible for maintaining the mobile node s reachability state (by tunnelling packets to MAG) MAG functionality: Resides on the access link where the MN is anchored Performs the mobility management on behalf of a MN MAG is responsible for detecting the MN s movements to and from the access link and for initiating binding registrations to the mobile node s LMA Emulates the MN s home link (by sending Router Advertisement messages containing the MN s home network prefix(es))
Architecture reference model Non-roaming architecture UTRAN SGSN UE LTE-Uu GERAN S3 S1-MME MME S11 S10 E-UTRAN S1-U HSS S6a S4 Serving Gateway S12 S5 Gx PDN Gateway PCRF SGi Rx Operator's IP Services (e.g. IMS, PSS etc.) Non-roaming architecture for 3GPP accesses source: TS23.401 ver. 13.5.0. 34 General Packet Radio Service enhancements for Evolved Universal Terrestrial Radio Access Network access.
Architecture reference model Roaming architecture HSS PCRF Gx Rx S6a PDN Gateway SGi Operator s IP Services (e.g. IMS, PSS etc.) HPLMN VPLMN UTRAN S8 SGSN GERAN S1 - MME S3 MME S4 S12 UE LTE - Uu E - UTRAN S10 S 1 - U S11 Serving Gateway Roaming architecture for 3GPP accesses. Home routed traffic. source: TS23.401 ver. 13.5.0. 35 General Packet Radio Service enhancements for Evolved Universal Terrestrial Radio Access Network access.
Non-3GPP Access Networks are IP access networks that use access technology whose specification is out of the scope of 3GPP. The EPS supports the use of non-3gpp IP access networks to access the EPC. A Non-3GPP IP access network can be considered Trusted or Untrusted. It is not a characteristic of the access network: In non-roaming scenario it is the HPLMN's operator decision if a Non-3GPP IP access network is used as Trusted or Untrusted. In roaming scenario, the HSS or AAA Server in HPLMN makes the decision of whether a Non-3GPP IP access network is used as Trusted or Untrusted. 36
Summary MIPv6: Host-based mobility protocol MN and CN participate in the protocol Supports inter and intra-domain handovers Significant handover latency PMIPv6: Network-based mobility protocol Transparent to MN and CN Supports only intra-domain handovers Low handover latency. 37