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Redes Inalámbricas – Tema 5 Vehicular Networking General overview Technologies WAVE CALM Mobility Thanks to: • Knut Evensen - CVIS Chief Architect •John Moring •Vinod Kone •Jeonghoon Mo @ WINE LAB, Information and Communications University REDES INALÁMBRICAS Máster de Ingeniería de Computadores-DISCA 2 MIC 2009/2010 REDES INALÁMBRICAS Motivation Safety and transport efficiency In Europe around 40,000 people die and more than 1.5 millions are injured every year on the roads Traffic jams generate a tremendous waste of time and of fuel Most of these problems can be solved by providing appropriate information to the driver or to the vehicle REDES INALÁMBRICAS MIC 2009/2010 3 Motivation: other scenarios REDES INALÁMBRICAS MIC 2009/2010 4 Motivation: other scenarios 5 MIC 2009/2010 Motivation: Sensor networks on the road Position sensors GPS, accelerometer, compass, tilt sensor Environment sensors CO2, cameras, thermometer, barometer, humidity sensor Vehicle sensors REDES INALÁMBRICAS ignition, speed, engine speed, engine temperature, … Source: Davies, Cottingham, Jones: A Sensor Platform for Sentient Transportation Research, LNCS 4272. Oct. 2006. Vehicle interior sensors camera, ID card reader 6 MIC 2009/2010 REDES INALÁMBRICAS Technology trends Wi-Fi (and possibly WiMAX) enabled vehicles are expected to be on the road within the next 3-5 years. Assuming 10% market penetration, this amounts to ~3-4 million Wi-Fi enabled vehicles in the UK, and ~20 million in the US in near future. FCC has allocated 75 MHz of spectrum exclusively for V2V and V2I wireless communications (total UK 3G spectrum is ~ 70 MHz). In the UK and across the EU 30 MHZ of spectrum has been put aside for vehicular networks. Vehicles equipped with WiFi can communicate directly with each other (V2V), and with the fixed infrastructure (V2I). They can form Vehicular Adhoc Networks (VANET) 7 MIC 2009/2010 Vehicular Ad Hoc Network (VANET) Vehicular Ad Hoc network (VANET) Uses equipped vehicles as the network nodes Nodes move at will relative to each other but within the constraints of the road infrastructure REDES INALÁMBRICAS VANETs vs MANETs Rapid Topology Changes High relative speed of vehicles => short link life Frequent Fragmentation Chunks of the net are unable to reach nodes in nearby regions Small Effective Network Diameter A path may cease to exist almost as quickly as it was discovered (reactive routing) Limited Redundancy The redundancy in MANETs is critical to providing additional bandwidth In VANETs the redundancy is limited both in time and in function 8 MIC 2009/2010 So what kind of a system do we need? Desirable system properties Data collection and distribution in a local environment Low information delivery latency Cheap deployment and communication Probable solutions Cellular ? Service fees Satellite ? High latency Vehicular Networks ? REDES INALÁMBRICAS What is a vehicular network? Vehicles are equipped with sensing, computing and wireless devices Vehicles talk to road-side infrastructure (V2I) and other vehicles (V2V) Has all the desirable properties 9 MIC 2009/2010 Vehicular Networks What does road-side infrastructure (Infostation) mean? High bandwidth & Low cost device Coverage is less compared to a cellular base station Advantages of infrastructure support REDES INALÁMBRICAS Low latency communication with vehicles Gateway to the Internet and extend connectivity Distributing time-critical data (e.g. accident notifications, traffic jam) near the affected area is efficient 10 MIC 2009/2010 Data Dissemination approaches and tradeoffs Vehicular networks need to handle large amounts of data (emergency messages, videos etc) How do we efficiently disseminate this information? REDES INALÁMBRICAS Characteristics High mobility Dynamic topology Receivers are a priori unknown Large scale High density Low penetration ratio Challenges Maintaining routing tables is difficult Scalability Dealing with partitions 11 MIC 2009/2010 Classification of Dissemination Approaches V2I / I2V dissemination Push based Pull based V2V dissemination Flooding Relaying How to deal with network partitions? REDES INALÁMBRICAS Opportunistic forwarding 12 MIC 2009/2010 V2I / I2V dissemination Push based Pull based V2V dissemination Flooding Relaying How to deal with network partitions? Opportunistic forwarding Push based dissemination Infostation pushes out the data to everyone Applications: Traffic alerts, Weather alerts Why is this useful? REDES INALÁMBRICAS Good for popular data No cross traffic Low contention Drawback Everyone might not be interested in the same data 13 MIC 2009/2010 V2I / I2V dissemination Push based Pull based V2V dissemination Flooding Relaying How to deal with network partitions? Opportunistic forwarding Pull based dissemination Request – Response model Applications: Email, Webpage requests Why is this useful? REDES INALÁMBRICAS For unpopular / user-specific data Drawback Lots of cross traffic Contention, Interference, Collisions 14 MIC 2009/2010 V2I / I2V dissemination Push based Pull based V2V dissemination Flooding Relaying How to deal with network partitions? Opportunistic forwarding Basic Idea Broadcast generated and received data to neighbors Usually everyone participates in dissemination Advantages “Good” for delay sensitive applications Suitable for sparse networks Key Challenges REDES INALÁMBRICAS How to avoid broadcast storm problem? Flooding 15 MIC 2009/2010 V2I / I2V dissemination Push based Pull based V2V dissemination Flooding Relaying How to deal with network partitions? Opportunistic forwarding Techniques to avoid the broadcast problem Simple forwarding Timer based Hop limited Map based / Geographic forwarding Directed flooding Aggregation REDES INALÁMBRICAS Drawbacks / Limitations of Flooding Flooding in general High message overhead Not scalable Map based / Geographic Geographically closest doesn’t necessarily reflect the best path! Depend on a location based service Aggregation techniques tradeoff with accuracy 16 MIC 2009/2010 V2I / I2V dissemination Push based Pull based V2V dissemination Flooding Relaying How to deal with network partitions? Opportunistic forwarding Basic Idea Instead of flooding the network, select a relay (next hop) Relay node forwards the data to next hop and so on Advantages Reduced contention Scalable for dense networks Key Challenges REDES INALÁMBRICAS How to select the relay neighbors? How to ensure reliability? Relaying 17 MIC 2009/2010 V2I / I2V dissemination Push based Pull based V2V dissemination Flooding Relaying How to deal with network partitions? Opportunistic forwarding How to select a relay neighbor? Simple forwarding Select the node farthest from source Map based / Geographic forwarding Closest to the destination Abstract topology into a weighted directed graph Drawback / Limitations REDES INALÁMBRICAS Locally best next hop may not be globally best ! 18 MIC 2009/2010 V2I / I2V dissemination Push based Pull based V2V dissemination Flooding Relaying How to deal with network partitions? Opportunistic forwarding How to ensure reliability? Use RTS/CTS & ACK Use indirect acknowledgments Drawbacks / Limitations REDES INALÁMBRICAS RTS/CTS incurs lot of overhead Interference affects indirect acknowledgments 19 MIC 2009/2010 V2I / I2V dissemination Push based Pull based V2V dissemination Flooding Relaying How to deal with network partitions? Opportunistic forwarding Opportunistic Forwarding Problem with partitioned networks Next hop is not always present Opportunistic Forwarding Basic Idea: Store and Forward Challenge: What is the right re-broadcast interval? Solutions REDES INALÁMBRICAS Broadcast repeatedly Cache at infostations 20 MIC 2009/2010 V2I / I2V dissemination Push based Pull based V2V dissemination Flooding Relaying How to deal with network partitions? Opportunistic forwarding Opportunistic: Drawbacks / Limitations It is difficult to select the correct re-broadcast interval Too soon high overhead Too late doesn’t deal with partitions effectively REDES INALÁMBRICAS Maintaining a neighbor list induces high overhead and contention 21 MIC 2009/2010 REDES INALÁMBRICAS Take Away V2I/I2V Dissemination Pros Cons Push Suitable for popular data Not suitable for un-popular data Pull Suitable for un-popular/ user-specific data Cross traffic incurs heavy interference, collisions V2V Dissemination Pros Cons Flooding Can reliably & quickly distribute data Not scalable for dense networks Relaying Works well even in dense networks Selecting best next hop & reliability is difficult Dissemination in Partitioned networks Pros Cons Opportunistic Suitable for network partitions Difficult to estimate re-broadcast interval High overhead in dense networks 22 MIC 2009/2010 EU activities Political, Social and Economic Interests Harmonization REDES INALÁMBRICAS Specifications European Projects Etc. Convening Stimulation Moderation Editoring Dissemination Standardisation ETSI CEN Group of Experts Combination Clarification C2C-CC IEEE ITU ISO IETF 23 MIC 2009/2010 Numerous Systems and Standards are under Construction… A variety of EU and national projects elaborate Protocol Architectures, System Architectures, High-Level Architectures ....... REDES INALÁMBRICAS Do we really need yet another Communication - Architecture ? Yes, because a comprehensive framework is needed to enable individually developed components to cooperate easily Source: Timo Kosch, BMW ITS Station Reference Architecture Joint development: SM-SAP ETSI TC ITS COMeSafety + R&D projects Traffic Efficiency Other Applications SA-SAP Road Safety SA-SAP MA-SAP MA-SAP Station management Security NF-SAP NF-SAP Networking & Transport SN-SAP ... + IPv6 Mobility Extensions SI-SAP GeoOther Routing protocols SN-SAP ITS Network TCP/UDP SI-SAP MN-SAP MN-SAP ITS Transport IN-SAP Firewall and Intrusion Management Session Support SF-SAP Information Support SF-SAP MF-SAP MF-SAP Application Support Security Information Base (Identity, CryptoKey and Certificate Managment) FA-SAP Facilities Authentication, Authorization, Profile Management FA-SAP IN-SAP MI-SAP Access Technologies (PHY&DLL) MI-SAP Management Networking Management Management Information Base (MIB) REDES INALÁMBRICAS SM-SAP Applications Cross-Interface Management 24 MIC 2009/2010 Proposed European ITS Communication Architecture Station-External Interfaces e.g. 5.9GHz e.g. WiFi Station-Internal Interfaces e.g. e.g. e.g. e.g. GPS BlueTooth 2G/3G/... Ethernet Hardware Security Module (HSM) Redes Inalámbricas – Tema 5 Vehicular Networking General overview Technologies WAVE CALM Mobility Thanks to: • Knut Evensen - CVIS Chief Architect •John Moring •Vinod Kone •Jeonghoon Mo @ WINE LAB, Information and Communications University REDES INALÁMBRICAS Máster de Ingeniería de Computadores-DISCA MIC 2009/2010 Wireless technologies for BWA Wi-Fi 802.11a/b/g WiMAX DSRC 802.16d/e 802.11p ( WAVE) Range up to1000 m up to 4 km up to 40 km Up to 250 m data rate 11-54 Mbps 384 Kbps – 2Mbps, 14Mbps 10-100 Mbps 54 Mbps spectrum 2.4 GHz (b/f) 2.5 GHz (US), 5.9 GHz 5.2 GHz (f) 1900 to 1980 MHz and 2110 to 2170 MHz (UK) licence licence-exempt licensed Licensed & licenceexempt dedicated spectrum access mechanism contention-based centrally scheduled centrally scheduled contention based limitations •Interference issues due to shared spectrum •high deployment costs •high deployment costs short range •lower transmission rates, centralised. •centralised •already available, •high data rates • high coverage •large coverage •short range REDES INALÁMBRICAS 3G advantage •low deployment cost, •distributed 3.5, 2.3/2.5, 5 GHz •low deployment costs •Distributed 26 MIC 2009/2010 REDES INALÁMBRICAS 802.11b at speeds II: speed dependence Experiments performed under no-interference conditions (desert) External antenna on the roof UDP, TCP, HTTP Observed some velocitydependent packet loss Gass, Scott, Dio, 2005. Redes Inalámbricas – Tema 5 Vehicular Networking General overview Technologies WAVE CALM Mobility Thanks to: • Knut Evensen - CVIS Chief Architect •John Moring •Vinod Kone •Jeonghoon Mo @ WINE LAB, Information and Communications University REDES INALÁMBRICAS Máster de Ingeniería de Computadores-DISCA 29 MIC 2009/2010 WAVE Scope Host Host ON-BOARD UNITS External Systems OBU OBU Applications Host Host WAVE Stack WAVE Stack WAVE Stack WAVE Stack Wireline Stack Wireline Stack Applications Optional External Interface REDES INALÁMBRICAS Covered by WAVE Standards Air Interface Wireline Stack Wireline Stack ROAD SIDE UNIT Wireline Stack Wireline Stack External Systems In Vehicle In Vehicle Optional Network Network External Interface 30 MIC 2009/2010 Protocol Architecture Data Plane Management Plane UDP / TCP WSMP Management Security IPv6 LLC WAVE MAC (including channel coordination) Air Interface REDES INALÁMBRICAS PHY 31 MIC 2009/2010 Trial Use Standards IEEE Std 1609.1-2006 WAVE device WAVE IEEE 1609.2 Service Security Resource Manager Upper Layers IEEE 1609.1, et al. Networking Services IEEE 1609.3 Lower Layers IEEE 1609.4, IEEE 802.11p IEEE Std 1609.2-2006 Security Services IEEE Std 1609.3-2007 Networking Services IEEE Std 1609.4-2006 Multi-Channel Operation IEEE P802.11p - draft REDES INALÁMBRICAS WAVE MAC and PHY IEEE Std 802.11-1999 Medium MAC and PHY 32 Future higher layer standards MIC 2009/2010 Full Use Standards in process 1609.2 WSMP REDES INALÁMBRICAS WAVE MAC (including channel coordination) PHY 802.11 LLC 1609.4 Management Security IPv6 1609.3 UDP / TCP 33 MIC 2009/2010 Overview of 802.11p (D7.0) Specifies channelization in the 5.9 GHz band Tunes some RF specs to allow highway operation Defines a mode of operation “outside the context of a basic service set” Removes latency-causing link setup operations such as authentication REDES INALÁMBRICAS Defines a Time Advertisement message 34 MIC 2009/2010 Overview of 1609.4 Multi-Channel Operation Extensions to the 802.11/802.11p MAC Management plane (MLME: MAC SubLayer Management Entity) Manages optional regular switching between control channel and service channel Queues regular time advertisements and/or service advertisements Data plane (MAC) REDES INALÁMBRICAS Multiplexes/demultiplexes higher layer protocols (IPv6, WSMP) Queues messages for transmission on the correct channels Manages transmit message priority 35 MIC 2009/2010 1609 Channel Coordination examples CCH Interval SCH Interval CCH Interval SCH Interval Time a) CCH Continuous access Control Channel: management and (high priority) messages b) CCH SCH Alternating access Service Channel: general user message and IP traffic c) CCH REDES INALÁMBRICAS SCH d) CCH SCH Immediate access For devices that don’t need continuous CCH access Extended access 36 MIC 2009/2010 1609.4 Transmit Operation LLC MAC (with Muti-Channel Operation) Channel Routing AC=4 AC=1 AC=2 AC=3 AC=4 AIFS[AC] CW[AC] TXOP[AC] AIFS[AC] CW[AC] TXOP[AC] AIFS[AC] CW[AC] TXOP[AC] AIFS[AC] CW[AC] TXOP[AC] AIFS[AC] CW[AC] TXOP[AC] 802.11p MAC (CCH) AC=3 AIFS[AC] CW[AC] TXOP[AC] AIFS[AC] CW[AC] TXOP[AC] AC=2 AIFS[AC] CW[AC] TXOP[AC] AC=1 REDES INALÁMBRICAS SCH (WSM and/or IP data) CCH (WSM data only) Internal Contention Internal Contention Channel Selector and Medium Contention Transmission Attempt Management frames 802.11p MAC (SCH) Management frames 37 MIC 2009/2010 Overview of 1609.3 Networking Services Management plane (WME: WAVE Management Entity) Generates contents of service advertisements based on higher layer info Including IP configuration info and security credentials Monitors received service advertisements for services of interest to higher layers Estimates channel quality Determines channel allocation/switching schedule to satisfy service requests Data plane REDES INALÁMBRICAS Incorporates standard LLC and IPv6 Introduces thin WAVE Short Message Protocol (WSMP) Allows direct control of RF parameters (e.g., power, data rate) by the higher layer 38 MIC 2009/2010 WAVE Short Message Protocol (WSMP) Messages transmitted on request by higher layer Dest. MAC address, User Priority, Channel, Data rate, Transmit Power, PSID Messages delivered over the air by MAC address Unicast or broadcast Messages delivered up the stack by protocol and PSID EtherType distinguishes WSMP from IP Higher layer Peer MAC address Dest_ address REDES INALÁMBRICAS Dest address User priority Priority Priority Channel number Channel number Channel number Data rate Data rate Data rate TxPwr_ Level TxPwr_ Level TxPwr_ Level Expiry Time PSID Expiry Time Expiry Time 1 1 DSAP= 0xAA SSAP= 0xAA 1 3 Length WSM data 1 4 Var. 1 2 Var. WSMP version PSID Ext. fields WSM element ID WSM length WSM data WME-Wave ShortMessage.req WSMP DLUNITDATA.req LLC 2 Control= OUI= EtherType 0x03 0x000000 =0x88DC WSMP Header WSM data MAUNITDATA.req MAC LLC header SNAP header Data field 39 MIC 2009/2010 “Services” Provider role Sends out WAVE Service Advertisements (WSAs) on control channel Includes info on services and channels May include IP configuration info In Trial Use, included timing info – now separate Operates on identified service channel(s) at designated times for application data exchange User role REDES INALÁMBRICAS Monitors WSAs for services of interest May visit identified service channels at designated times for application data exchange Allocation of radio resources to communication channels performed by 1609 stack based on higher layer request priority, service availability, device capabilities 40 MIC 2009/2010 WAVE Service Advertisement (WSA) contents 1 1 Var. 1 WAVE version Repeats Extension fields Provider Service Table WAVE Routing Advertisement Transmit Power Used 2D/3D Location IP configuration info Advertiser Identifier Service Info Channel Info 1 2 16 1 16 6 16 Var. WAVE Element ID Router lifetime IpPrefix Prefix length Default gateway Gateway MAC address Primary DNS Extension fields Secondary DNS KEY KEY Optional Optional Field Extension fields Lengths in octets Lengths in octets REDES INALÁMBRICAS Info about available services PSC IPv6 Address 1 4 1 WAVE Element ID PSID Service Priority 1 Var. Channel Extension fields Number Info about service channels 1 1 1 1 1 Var. WAVE Element ID Channel Number Adaptable Data Rate TxPwr_ Level Extension fields EDCA Parameter Set Service Port Provider MAC Address May be repeated May be repeated 41 MIC 2009/2010 Example of WAVE Transmit Protocol Layers This illustrates content from the higher layers, processed by the WAVE stack, and sent out as a service advertisement in an 802.11 frame Higher layer Service info WMEProviderService.req WME WSA Header PST SEC-SignWSA.req WRA Security Services Security Header WaveService Advertisement Security Trailer SEC-SignWSA.cfm IEEE 1609 WME MLMEX-WSA.req WSA MLME extension OUI Content descr. MLMEVSPECIFIC.req WSA MLME Cate gory OUI Vendor Specific Content REDES INALÁMBRICAS MAC MAC Header Vendor Specific Action frame IEEE 802.11 MAC Trailer PHY PHY Header Air interface 42 MIC 2009/2010 PSID & PSC Provider Service Identifier (PSID) 4 octets; values allocated by IEEE Used as WSMP recipient address, and Used as primary identifier of services in WAVE Service Advertisement Presumably identifies type of information and encoding to be found on the SCH Provider Service Context (PSC) REDES INALÁMBRICAS 0-32 octets; meaning determined by PSID Used as optional secondary service descriptor in WSA May indicate information sub-type, date tag, security context, etc. Redes Inalámbricas – Tema 5 Vehicular Networking General overview Technologies WAVE CALM Mobility Thanks to: • Knut Evensen - CVIS Chief Architect •John Moring •Vinod Kone •Jeonghoon Mo @ WINE LAB, Information and Communications University REDES INALÁMBRICAS Máster de Ingeniería de Computadores-DISCA 44 MIC 2009/2010 CALM - Overall Continuous Air interface for Long and Medium distance REDES INALÁMBRICAS ISO TC204/WG16 – Wide Area Communications Support user transparent continuous communications CALM is the first open way to combine GPRS with vehicleoptimized WLAN technology. NOT a complicated collection of new, unproven radio technologies 45 MIC 2009/2010 REDES INALÁMBRICAS Services defined for 5 GHz medium - 1 CVO - Tractor-Trailer Interface CVO - Rollover Warning CVO - Electronic Border Clearance CVO - Weigh Station Bypass Clearance CVO - CVO Fleet Management CVO - Onboard Safety Data Transfer CVO - Tractor-Trailer Matching CVO - Transit Vehicle Data Transfer CVO - Vehicle Safety Inspection CVO - Drivers Daily Log OTHER SERVICES - Probe Data Collection OTHER SERVICES - Access Control OTHER SERVICES – Vehicle Manufacturer Info PAYMENTS - Toll Collection PAYMENTS - ITS Service Payment PAYMENTS - Other ePayments PAYMENTS - Rental Car Processing PAYMENTS - Parking Payment PAYMENTS - Food Payment PAYMENTS - Fuel Payment SAFETY - Vehicle-to-vehicle Data Transfer SAFETY – Highway-Rail Intersection Warning Traffic Information - Audio Transfer - Streaming Traffic Information - Map Updates Traffic Information - Mobile Internet Traffic Information - Traffic Data Traffic Information - Traveller Information Traffic Information - Vehicle Registration (EVI) Traffic Information - Transit Vehicle Priority Traffic Information - Diagnostic Data Transfer Traffic Information - Video Transfer - Block Traffic Information - Audio Transfer - Block Traffic Information - Video Transfer - Streaming Traffic Information - Repair Service Record Traffic Information - Vehicle Software Updates VSC - OBU-to-OBU - Approaching Emergency Vehicle Warning VSC - OBU-to-RSU - Emergency Vehicle Signal Pre-emption VSC - OBU-to-RSU - Intersection Emergency Vehicle Approaching VSC - RSU to OBU - Emergency Scene Data Networking VSC - OBU-to-OBU - Emergency Scene Data Networking VSC - OBU-to-OBU - Cooperative Collision Warning 46 MIC 2009/2010 REDES INALÁMBRICAS Services defined for 5 GHz medium - 2 VSC - RSU to OBU VSC - RSU to OBU Navigation VSC - RSU to OBU VSC - RSU to OBU VSC - RSU to OBU VSC - RSU to OBU VSC - RSU to OBU VSC - RSU to OBU VSC - RSU to OBU VSC - RSU to OBU VSC - RSU to OBU VSC - RSU to OBU VSC - RSU to OBU VSC - RSU to OBU VSC - RSU to OBU VSC - RSU to OBU VSC - RSU to OBU VSC - RSU to OBU Warning VSC - RSU to OBU VSC - RSU to OBU VSC - RSU to OBU VSC - RSU to OBU VSC - RSU to OBU VSC - RSU to OBU - Map Downloads and Updates - Enhanced Route Guidance and - GPS Corrections Adaptive Headlight Aiming Adaptive Drivetrain Management Merge Assistant Sign Information (warning assistance) Point-of-Interest Notification Curve Speed Warning Highway/Rail Collision Warning Animal Crossing Zone Information Low Bridge Warning Work Zone Warning Stop Sign Warning Keep Clear' Warning Wrong-way Driver Warning Left Turn Assistant Infrastructure Intersection Collision - Pedestrian Crossing Information Pedestrian/Children Warning School Zone Warning Stop Sign Movement Assistance Traffic Signal Warning Low Parking Structure Warning VSC - OBU-to-OBU - Pre-crash Sensing VSC - OBU-to-OBU - Intersection Collision Warning VSC - OBU-to-OBU - Enhanced Differential GPS Corrections VSC - OBU-to-OBU - Highway/Rail Collision Warning VSC - OBU-to-OBU - Vehicle-based Road Condition Warning VSC - OBU-to-OBU - Road Feature Notification VSC - OBU-to-OBU - Curve Speed Warning VSC - OBU-to-OBU - Visibility Enhancer VSC - OBU-to-OBU - Electronic Brake Lights VSC - OBU-to-OBU - Hybrid Intersection Collision Warning VSC - OBU-to-OBU - Instant (Problem) Messaging VSC - OBU-to-OBU - Blind Merge Warning VSC - OBU-to-OBU - Post-Crash Warning VSC - OBU-to-OBU - Merge Assistant VSC - OBU-to-OBU - Lane Change Assistant VSC - OBU-to-OBU - Left Turn Assistant VSC - OBU-to-OBU - Stop Sign Movement Assistant VSC - OBU-to-OBU - Cooperative Glare Reduction VSC - OBU-to-OBU - Blind Spot Warning VSC - OBU-to-OBU - Platooning VSC - OBU-to-OBU - Cooperative Adaptive Cruise Control VSC - OBU-to-RSU - Infrastructure-based Traffic Probes VSC - OBU-to-RSU - SOS Services VSC - OBU-to-RSU - Post-Crash Warning VSC - OBU-to-RSU - Just-in-Time Repair Notification VSC - OBU-to-RSU - Intelligent On-ramp Metering VSC - OBU-to-RSU - Intelligent Traffic Lights VSC - OBU-to-RSU - Blind Merge Warning 47 MIC 2009/2010 CALM classic architecture ISO TC204 ITS APPLICATIONS Service QoS HTTP/ SMTP Protocols Stream & Realtime Protocols ISO DSRC L7 Interface Selection TCP UDP L2/UDP REDES INALÁMBRICAS IPv6 layer Handover Interface QoS Init Hndovr Secur MAC 802.11p WAVE Init Hndovr Secur MAC 2G/3G GSM Init Hndovr Secur MAC GPS/Galileo … 48 MIC 2009/2010 CALM System Architecture (21217) (Rev. Geneva) CME CALM Manager ISO 21210 CME Registration of Ingress/Egress Interfaces Application Management ISO 24101 SAP SAP SAP Convergence Layer IP socket/ ISO 21210 TCP/UDP/… INTERNET STANDARDS SAP SAP CALM-Aware APPLICATIONS SAP SAP SAP SAP NME Network SAP Manager ISO 21210 SAP SAP NETWORK INTERFACE Routing and Media Switching based on IPv6 ISO 21210 SAP SAP SAP SAP SAP SAP ISO 21218 ISO 24xxx Wired Manager CAN AMIC Ether BlueT Applications W-USB Management SAP SAP ISO 21218 ISO 24xxx PAN Manager … SAP GPS Data SAP DAB External Media CALM Network 21218 = LSAP SAP ISO 21218 ISO 24xxx Broadcast Manager … WiMAX HC-SDMA C-DSRC ISO 21218 ISO 24xxx W-MAN Manager J-DSRC ISO 21218 ISO 24103 DSRC ISO15628 MM-E ISO 21218 ISO 21216 Millimeter Manager MM-J M5 WiFi … SAP IR-A IR-B … UMTS cdma2k … EDGE GPRS CALM Media ISO 21218 ISO 21215 W-LAN Manager SAP … ISO 21218 ISO 21214 IR Manager SAP K-DSRC ISO 21218 ISO 21213 3G Cell Manager SAP RADAR ISO 21218 ISO 21212 2G Cell Manager … REDES INALÁMBRICAS Non-CALM-aware IP (Internet) APPLICATIONS Convergence Layer Part of ISO 15628 ISO 21210 SAP IME SAP Interface Manager ISO 24102 Non-CALM-aware ISO 15628-based APPLICATIONS 49 MIC 2009/2010 Vehicle Architecture CALM Network Layer Ethernet Ethernet ITS In-Vehicle Network 100baseT Ethernet Real-time Applications CVIS Integrated Mobile Router Network REDES INALÁMBRICAS C2C-CC Fast Net Network DSRC CALM LLC Convergence CALM MAC Ethernet RT Link Sensors, HMI and Control In-Vehicle App IVN DLL IVN DLL IVN PHY IVN PHY In-vehicle OEM networks CAN/VAN/MOST/AMI-C.. Nomadic device Gateway CALM Routing Network Ethernet Ref pt C2C Switch Layer Firewall OEM G/W Real-time Applications CALM M5 PHY DSRC L2/L7 DSRC L1 Comms gateway Network Network GPRS Convergence GPS Convergence GPRS Stack GPS Stack Bluetooth GPS PHY Bluetooth GPRS PHY Combined Antenna Pod CME. Router NME. Router IME. Router 50 MIC 2009/2010 Communication Scenarios CALM defines 5 communication scenarios: 0 – V2I Non-IPv6 (WSMP or C2C-CC?) 1 – V2I/V2V Local IPv6 2 – V2I MIPv6 3 – V2I NEMO 4 – V2V Non-IPv6 (WSMP or C2C-CC?) HA CN Internet REDES INALÁMBRICAS Access Router Mobile Router LFN LFN LFN 51 MIC 2009/2010 What is CALM M5? US DSRC (WAVE) WAVE is IEEE 802.11p, as required by US DoT/VSCC/VII/… WAVE is optimised for US channel plan WAVE protocols are optimised for current single-radio technology. No GSM or other technology is included. CALM M5 incorporate WAVE and adds: REDES INALÁMBRICAS Global (European) 5 GHz spectrum Regulatory domain (border) management Directivity and EMC control CEN DSRC co-operation Multiple radio/interface/antenna management GPRS/UMTS network interconnectivity 52 MIC 2009/2010 CALM M5: C2C-CC & WAVE Geoaddressed applications (e.g. active safety) IP Applications (Deployment) WAVE Short Message Apps WSMP TCP / UDP IPv6 B C2C-CC Network Layer REDES INALÁMBRICAS A C2C MAC B LLC/MAC (IEEE 802.11p) PHY (IEEE 802.11p) C P1609.4 Redes Inalámbricas – Tema 5 Vehicular Networking General overview Technologies WAVE CALM Mobility Thanks to: • Knut Evensen - CVIS Chief Architect •John Moring •Vinod Kone •Jeonghoon Mo @ WINE LAB, Information and Communications University REDES INALÁMBRICAS Máster de Ingeniería de Computadores-DISCA 54 MIC 2009/2010 Mobility Mobility is the key issues in Vehicular Networks In cellular based networks, handoff is a mature technique Handoff in GSM networks Handoff in CDMA networks In IP based networks, handoff is immature WiMax, Wi-Fi REDES INALÁMBRICAS Vertical handoff, NEMO are being pursued… 55 MIC 2009/2010 Different Types of Mobility Scale Pico Micro Macro Global Network Vertical Handoff Horizontal Handoff REDES INALÁMBRICAS Moving Entity Host mobility User Mobility Application Mobility Network Mobility 56 MIC 2009/2010 REDES INALÁMBRICAS How to handle Mobility? Where can we address this problem? Physical layer? (sure; very limited) Link layer Network layer Transport layer “Something higher” (often called session) Application layer 57 MIC 2009/2010 REDES INALÁMBRICAS How to handle Mobility? Where can we address this problem? Physical layer? (sure; very limited) Link layer Network layer Transport layer “Something higher” (often called session) Application layer Possible to code many applications to deal with disconnection It’s all about trying to resume and managing state But should the burden be placed on every application developer? 58 MIC 2009/2010 Link-layer mobility What timescales does it support? Pretty durned fast Have the link layer mask mobility E.g., the campus 802.11 wireless. You can move anywhere and keep the same MAC and IP address Completely transparent. No OS/App support needed. Brilliant! Fast & Local: Only switches near moving client must be updated. But – only local! Can’t move out of your subnet. How about different links, different technologies? REDES INALÁMBRICAS IEEE 802.21 59 MIC 2009/2010 IP Layer Mobility Allow hosts to take their “home” IP address with them wherever they go. Advantages: Potentially global mobility scope (not limited to subnet like link layer) Transparent to applications and layers above IP REDES INALÁMBRICAS How can we do it? 60 MIC 2009/2010 Brute Force: IP routing If node leaves home, send out (global?) routing announcement pointing to new location In theory, “just works” Example: Boeing’s “Connexion” announced a /24 into BGP for every supported airplane and moved the announcement to the gateway the plane was closest to Why? Latency concerns over really long flights (start in SF, end in London) Already have high latency from using satellites. But wouldn’t scale for single IP addresses REDES INALÁMBRICAS Every AS in world would have routing entry for every mobile user in the world? Ouch! Problem: Having the whole world maintain state for every user Alternative: Keep state local, by… 61 MIC 2009/2010 Mobile IP (& others): Same as other problems in Computer Science Add a level of indirection Keep some part of the network informed about current location Need technique to route packets through this location (interception) REDES INALÁMBRICAS Need to forward packets from this location to mobile host (delivery) 62 MIC 2009/2010 Mobile IP RFC 3220 “IP Mobility Support for IPv4”, C. Perkins, Ed., Nokia Research Center, January 2002 has many features: home agents, foreign agents, foreign-agent registration, care-of-addresses, encapsulation (packet-within-a-packet) three components to standard: REDES INALÁMBRICAS indirect routing of datagrams agent discovery registration with home agent 63 MIC 2009/2010 IP Mobility: Principles Core network routing transparency Routers and switches are un-aware of mobility Host-controlled location update to effect routing path change Responsibility rests on the Mobile Node (MN) Adheres to the “end-to-end” model REDES INALÁMBRICAS Minimal network support Intelligent host 64 MIC 2009/2010 Solution Requirements Roaming: Roaming: Packets need to reach the current location of a Mobile Node Handover: REDES INALÁMBRICAS Connection (session) end-point must remain constant even though the IP address changes Connection end-point must be able to handle change of IP address 65 MIC 2009/2010 Mobile IP: indirect routing foreign-agent-to-mobile packet packet sent by home agent to foreign agent: a packet within a packet dest: 79.129.13.2 dest: 128.119.40.186 dest: 128.119.40.186 REDES INALÁMBRICAS Permanent address: 128.119.40.186 dest: 128.119.40.186 packet sent by correspondent Care-of address: 79.129.13.2 66 MIC 2009/2010 Mobile IP: agent discovery agent advertisement: foreign/home agents advertise service by broadcasting ICMP messages (typefield = 9) 0 type = 9 checksum =9 standard ICMP fields router address type = 16 length registration lifetime REDES INALÁMBRICAS 24 code = 0 =9 H,F bits: home and/or foreign agent R bit: registration required 16 8 sequence # RBHFMGV bits reserved 0 or more care-ofaddresses mobility agent advertisement extension 67 MIC 2009/2010 Mobile IP: registration example home agent HA: 128.119.40.7 foreign agent COA: 79.129.13.2 visited network: 79.129.13/24 ICMP agent adv. COA: 79.129.13.2 …. registration req. COA: 79.129.13.2 HA: 128.119.40.7 MA: 128.119.40.186 Lifetime: 9999 identification: 714 encapsulation format …. registration req. COA: 79.129.13.2 HA: 128.119.40.7 MA: 128.119.40.186 Lifetime: 9999 identification:714 …. REDES INALÁMBRICAS registration reply time HA: 128.119.40.7 MA: 128.119.40.186 Lifetime: 4999 Identification: 714 encapsulation format …. registration reply HA: 128.119.40.7 MA: 128.119.40.186 Lifetime: 4999 Identification: 714 …. Mobile agent MA: 128.119.40.186 68 MIC 2009/2010 Mobile IP Issues Route Optimization In order to always use HoA, packets need to be routed through the Home Agent introduces sub-optimal routing and hence potentially longer delay Direct communication between the MN and its correspondents should be possible Authentication Registration messages Binding cache updates Must send updates across network REDES INALÁMBRICAS Handoffs can be slow 69 MIC 2009/2010 Mobile IP Optimization Fast Handoff Handoff delay is too long Can we reduce it? FMIP, FMIPv6 Hierarchical Handoff REDES INALÁMBRICAS Frequent Binding Update incurs burden on Let’s handle the local movements inside the local network REDES INALÁMBRICAS MIC 2009/2010 70 Handoff Delay Illustration 71 MIC 2009/2010 Fast Handover Protocol Allows a MN to learn new Router information when still attached to the current router enables fast movement detection expedites new address configuration facilitates immediate transmission upon new link establishment Allows a MN to receive packets sent to its previous IP address until Binding Update to Home Agent is completed Binding Update to the correspondent is completed REDES INALÁMBRICAS Involves tunnel establishment triggered by MN signaling REDES INALÁMBRICAS MIC 2009/2010 72 Fast Handover Illustration REDES INALÁMBRICAS MIC 2009/2010 73 Delays with Fast Handover MIC 2009/2010 74 Hierarchical MIP: Macro Mobility and Micro Mobility Macro Mobility Domain-level, Mobile IP-based Micro Mobility Cell area, Hierarchical MIP REDES INALÁMBRICAS Home Agent 75 MIC 2009/2010 Transport-layer solution TCP Migrate Idea: No IP support; just have transport layer dynamically rebind endpoints MIGRATE Location Query (DNS Lookup) Location Update (Dynamic DNS Update) DNS Server REDES INALÁMBRICAS Connection Initiation Connection Migration Correspondent Host Mobile Host foo.bar.edu yyy.yyy.yyy.yyy xxx.xxx.xxx.xxx 76 MIC 2009/2010 Migrate Advantages: (Mostly) transparent to applications Unless they know their IP address and use it, e.g., peer-to-peer apps. Keeps state and modifications entirely at endpoints No triangle routing! All communication is direct But: REDES INALÁMBRICAS Requires TCP support / only works for TCP Not true in general: “Host ID Protocol” – HIP – can work with both, but requires more invasive IP stack changes Slower timescales than link-layer migration (several RTTs) MIC 2009/2010 REDES INALÁMBRICAS Other issues: Network Mobility (NEMO) Support The vehicle changes its point of attachment to the Internet Host Mobility Each node maintains Internet access Each host must perform Mobile IPv6 Network Mobility Only the mobile router(MR) maintains Internet access Nodes can be located behind the MR Host Mobility Support Mobile Router Network Mobility Support 7 7 78 MIC 2009/2010 Other issues: Host Identity Protocol (HIP) Considerable recent work: Give each host a unique identity Simplifies mobility Also simplifies multi-homing! (Many related issues) Deployment Issue Idea: IP address: changes with location HIP does not change Application-specific identifiers REDES INALÁMBRICAS Pairs <IP address, Port#> + Transport Protocol ID Host Identity (HI) Application Layer Transport Layer Host Identity IP addresses Network Layer Link layer addresses Data Link Layer