Download presentation
1
V2V and V2I Communication
건국대학교 MBC Lab
2
Contents V2I/V2V Communication Introduction DSRC WAVE CALM
V2V Network Protocols Projects and Standards
3
V2I/V2V Communication Introduction
1 비넷에 과한 강의를 시작하겠습니다.
4
Introduction What is ITS? Intelligent Transportation Systems
encompass a broad range of wireless and wireline communications-based information, control and electronics technologies can provide : help monitor manage traffic flow reduce congestion provide alternate routes to travelers enhance productivity save lives, time and money
5
Introduction V2V/V2I Service Perspective
ITS will be developed into next-generation Navigation, Safety, Convergence & Infotainment Services - Next-generation Navigation : Provide real time and bi-directional information - Safety : Anti-collision and safety service in intersection road - Convergence : Vehicle management and related services - Infotainment Service : Content download service such as movie and music V2V/V2I Communication Technology V2V Multi-hop Communication : Safety, Group communication V2I Communication : Convergence, Infotainment service
6
Introduction V2I V2V V2V Communication : Vehicle Multi-hop Networking
V2I Communication : Bi-directional Packet Communication RSE : Road Side Equipment TSP : Telematics Service Provider Cellular/WiBro Base-station TSP Server IP Backbone V2I GPS RSE RSE V2V Emergence Message Warning Message Warning Message Probe Data Real time Traffic Information TSP 서버는 Traffic info 와 map info contents User info등을 제공 GPS를 통해 위치 정보를 파악하여 사고 시 차고 차량이 사고 위치를 주변 노드(자동차) 들에게 Propergation 함 텔레매틱스 터미널 즉, 자동차는 위치정보를 TSP 서버로 전송하여 위치에 기반한 맞춤형 서비스를 제공받을 수 있다. 그러므로 양방향 서비스는 필수. Accident Occur
7
Introduction (Examples-1)
WISDOM(V2I) Information - Data Collection - Information Provision - Provide information to traffic information center Management - Traffic signal control (Optimization for bus, emergency car) - Driving speed control Safety - Accident Avoidance
8
Introduction (Examples-2)
VII(Vehicle Infrastructure Integration ) Traffic signal violation warning Public safety vehicle priority signal activation Provide traffic information
9
DSRC
10
DSRC What is DSRC (Dedicated Short Range Communications)?
an Transportation Specific Technology a short to medium range (1000m max generally 300m) communications service supports both Public Safety and Private operations (roadside to vehicle, vehicle to vehicle communication) provide very high data transfer (6-27 Mbps) rates where minimizing latency in the communication link Half duplex : One-way at a time for ITS applications, working in the 5.9 GHz band (U.S.) or 5.8 GHz band (Japan, Europe)
11
DSRC Technical Characteristics 5.850 to 5.925 GHz Bandwidth = 75 MHz
Shared, but Transportation is primary
12
DSRC Operating Characteristics IEEE 802.11p protocol
Vehicle speeds up to 100 mph (160km/h) Low latency: 50 ms Application priority: 8 levels Channel 172: vehicle safety only Security Encrypt using Public Key Infrastructure (PKI) Road Side Unit (RSU) Authentication On Board Unit (OBU) Privacy
13
DSRC DSRC Standards ASTM E2213 : Radio (Data Link) New IEEE 802.11p
IEEE : Application manager IEEE : Network service IEEE : Medium Access Control IEEE 1556 : Security
14
WAVE (IEEE p) 1 비넷에 과한 강의를 시작하겠습니다.
15
WAVE What is WAVE? IEEE Family of Standards for Wireless Access in Vehicular Environments Focused on following issues: Limitation of the lack of ubiquitous high-speed communications between vehicles and service provider Limitation of the lack of homogeneous communications interfaces between different automotive manufacturers define an architecture and standardized set of services and interfaces enable secure vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I)
16
WAVE consists of four standards: IEEE P1609.1 - Resource Manager
specifies the services and interfaces of the WAVE Resource Manager application defines data flows and resources defines command message formats and data storage formats specifies the types of devices that may be supported by the OBU(On Board Unit) IEEE P Security Services for Applications and Management Messages defines secure message formats and processing IEEE P Networking Services defines network and transport layer services defines Wave Short Messages IEEE P Multi-Channel Operations provides enhancements to the IEEE Media Access Control (MAC) to support WAVE operations
17
WAVE characteristic Max. Speed : 200Km/H
1000 m range must support 1 Mbps Approach : Active Bandwidth : 75 MHz ( GHz) Modulation : QPSK OFDM Channels : 7EA 10 MHz channels Data Rate : 10 MHz Channels : 6, 9, 12, 18, 24, and 27 Mbps 20 MHz Channels : 6, 9, 12, 18, 24, 36, 48, and 54 Mbps Max Tx Pwr : 28.8 dBm (at the antenna input) RSU and OBU Sensitivity : 82 dBm (QPSK) / - 65 dBm (64QAM)
18
WAVE WAVE : Scope
19
WAVE Protocol Stack MLME : MAC Layer Management Entity
PLME : Physical Layer Management Entity WME : WAVE Management Entity WSMP : WAVE Short Message Protocol
20
WAVE OSI versus WAVE Model WAVE Standard
Draft P802.11p: Wireless Access in Vehicular Environments (WAVE) Defines the lower layers (PHY and MAC) communications stack IEEE Std ™-2007: Trial-Use Standard for WAVE - Multi-Channel Operation Provides frequency band coordination and manage ment within the MAC layer IEEE Std ™-2007: Trial-Use Standard for WAVE - Networking Services Specifies operation and management of the communications stack WAVE Standard
21
CALM (Continuous Air interface for Long and Medium range)
22
CALM What is CALM? Continuous Air interface for Long and Medium range
ISO approved framework Provide heterogeneous packet-switched communication in mobile environments CALM framework supports user transparent continuous communications across various interfaces and communication media (802.11, p, , e, , 2G/3G/4G cellular systems, national ITS systems) being developed by ISO TC204/WG16 – Wide Area Communications CALM M5 = CALM - Microwave 5 GHz CLAM
23
CALM Overall targets Support continuous communications
Support ITS services and Internet services Support of next generation applications: Major push in Vehicle Safety Communication New commercial applications made possible by high data rate & long range Support master/slave and peer-peer modes Support user transparent networking spanning multiple media, media providers and beacons M5: No harmful cross-interference with regional DSRC standards M5: Support relevant ASTM / IEEE / ETSI Hiperlan modes
24
CALM Architecture CME : CALM Management Entity
SAP : Service Access Point NME : Network Management Entity 간략한 CALM의 구조
25
CALM CALM Network Scenario(1)
26
CALM CALM Network Scenario(2)
27
CALM Selected CALM media ISO 21212: 2G Cellular (GSM)
ISO 21213: 3G Cellular (UMTS) ISO 21214: InfraRed ISO 21215: M5 (802.11p) ISO 25112: WiMAX (802.16e) ISO 25113: HC-SDMA (802.20) ISO xxxxx: Bluetooth (802.15) ISO xxxxx: Ethernet (802.3)
28
CALM CALM M5 vs. 802.11p (WAVE) WAVE PHY/MAC is IEEE 802.11p
CALM M5 incorporates WAVE and adds following features : Global (European) 5 GHz spectrum Regulatory domain (border) management Directivity and EMC control Regional DSRC cooperation Multiple radios/interfaces/antenna management through network connection GPRS/UMTS/+++ network interconnectivity
29
V2V Network Protocols
30
V2V Network Protocols Issues of V2V protocols
Mobility Highly dynamic, hence An on-going session suffers frequent path breaks Bandwidth Constraint Use the Bandwidth optimally by keeping the overhead as low as possible Error-Prone Shared Radio Channel Find paths with less congestion Hidden and Exposed Terminal problem Mesh network and MANET routing protocols can solve these issues
31
V2V Network Protocols MANET Mobile Ad-hoc NETwork
IETF Working Group (1997.7) ※Infrastructure-less communication without static base-station or wired backbone network 마넷은 Mobile Ad-hoc Network의 약자로 이동 애드혹 네트워크에서 라우팅 기법을 연구하기 위해 IETF에서 1997년에 결성된 워킹그룹 이름이다. 애드-혹 네트워크는 인프라스트럭쳐 없이 노드들간 동적으로 토폴로지가 구성되어 동적인 데이터 전송을 수행한다. 이러한 노드들로 구성된 망을 MANET라고 한다. < MANET(이동 애드-혹 네트워크) > < 일반 무선 네트워크 >
32
V2V Network Protocols MANET Characteristic
Cannot assume, that every computer is within communication range of every other computer can connect to Internet by Gateway every nodes in MANET can be host or router Dynamic topology Self-starting No administrator Battery constraint, less computing power and mobility => needs another routing protocol different from wired-network < Independent > < connected to Infrastructure> MANET의 노드들은 독립적은 망으로 존재할 수도 있으며, 인터넷 망에 연결되어 있을 수도 있다. 여기서 중요한 점은 ad-hoc에서는 모든 노드가 서로간의 통신거리내에 없다고 해도 통신을 수행할 수 있다는 것이다. 이를 위해 모든 노드들은 호스트로서의 기능과 라우터의 기능을 동시에 수행하는 것이 MANET 노드들의 특징이다. 라우터의 기능을 수행하는 노드들의 빈번한 참가와 탈퇴가 발생하여 잦은 토폴로지의 변화를 가져와 예측이 힘듬. 노드들은 제한된 전력과 프로세싱 능력, 메모리 자원과 이동성에 관련해서 유선망과는 다른 라우팅 프로토콜이 요구됨
33
V2V Network Protocols Wireless Mesh Network Node Types Link Types
Wireless routers Gateways Printers, servers Mobile clients Stationary clients Intra-mesh wireless links Stationary client access Mobile client access Internet access links
34
Wireless Mesh Network : Gateways
V2V Network Protocols Wireless Mesh Network : Gateways Multiple interfaces (wired & wireless) Mobility Stationary (e.g. rooftop) – most common case Mobile (e.g., airplane, busses/subway) Serve as (multi-hop) “access points” to user nodes Relatively few are needed, (can be expensive) GW
35
Wireless Mesh Network : Wireless Routers
V2V Network Protocols Wireless Mesh Network : Wireless Routers At least one wireless interface. Mobility Stationary (e.g. rooftop) Mobile (e.g., airplane, busses/subway). Provide coverage (acts as a mini-cell-tower). Do not originate/terminate data flows Many needed for wide areas, hence, cost can be an issue.
36
Converges Wireless Mesh network and MANET
V2V Network Protocols Converges Wireless Mesh network and MANET Wireless Networking Single Hop Multi-hop Infrastructure-based (hub&spoke) Infrastructure-less (ad-hoc) Infrastructure-based (Hybrid) Infrastructure-less (MANET) 802.11 802.16 802.11 Bluetooth Cellular Networks Car-to-car Networks (VANETs) Wireless Sensor Networks Wireless Mesh Networks
37
V2V Network Protocols IP Backbone
What kind MANET Protocol is good for ITS/Telematics Networking? V2V and V2I convergence V2V Communication : MANET routing protocol V2I Communication : Mesh network IP Backbone TSP Server RSE has a roll like a WMN gateway RSE RSE RSE Vehicles can be a wireless routers Data forwarded by MANET Protocol Data
38
V2V Network Protocols MANET Protocols - proactive and reactive routing Algorithms Proactive(table-driven) maintains fresh lists of destinations maintains routes by periodically distributing routing tables main disadvantages Respective amount of data for maintenance Slow reaction on restructuring and failures Reactive(on-demand) finds a route on demand by flooding Route Request packets High latency time in route finding Excessive flooding can lead to network clogging MANET의 라우팅 프로토콜은 proactive와 reactive 방식으로 나눌 수 있으며 proactive는 table-driven, reactive는 on-demand 방식이라고 한다. 프로엑티브 방식 항상 최신의 루트 정보를 유지 주기적으로 또는 토폴로지 변화가 있을 때 네트워크 전체로 라우팅 정보를 전파 모든 이동 노드가 최신 토폴로지 정보를 유지 이러한 방식은 노드로 하여금 지연 없이 최적의 루트로 패킷을 라우팅할 수 있게 한다. 토폴로지의 변화가 심한 경우 토폴로지 정보를 전파하는 과정에서 오버헤드가 과도하게 증가하게 되는 단점이 있습니다. 리엑티브 방식은 패킷을 전달하는 시점에 루트의 탐색 수행 라우팅 프로토콜 메시지의 오버헤드는 적지만 전달하는 순간에 루트 탐색을 시작하므로 일정 시간의 탐색을 위한 지연이 발생 트래픽에 대한 전송 지연을 가져옴
39
V2V Network Protocols MANET – Classification of Ad-hoc Routing Protocols
40
V2V Network Protocols MANET – DSDV (Table Driven)
Destination-Sequenced Distance Vector Keep the simplicity of Bellman-Ford Avoid the looping problem Tag each routing table entry with a Destination sequence number Allow fast reaction to topology changes Make immediate route advertisement on significant changes in routing table wait with advertising of unstable routes Remain compatible in cases where a base station is available Proactive Each node maintains routing information for all known destinations Routing information must be updated periodically Traffic overhead even if there is no change in network topology Maintains routes which are never used
41
V2V Network Protocols MANET – DSDV : Transmitting Route Information
Routing information is transmitted by broadcast Updates are transmitted periodically or immediately when any significant topology change is available Rules to set sequence number information On each advertisement increase own destination sequence number (use only even numbers) If a node is no more reachable (timeout) increase sequence number of this node by 1 (odd sequence number) and set metric = Full dump: all information from the transmitting node Incremental dump: all information that has changed since the last full dump Full dump if incremental dump exceeds one NPDU (network protocol data unit)
42
V2V Network Protocols MANET – DSDV : Route Selection
Update information is compared to own routing table Select route with higher destination sequence number Select the route with better metric when sequence numbers are equal.
43
V2V Network Protocols MANET – DSDV : Problem
DSDV requires a full dump update periodically DSDV is not efficient in route updating DSDV limits the number of nodes that can join the network Whenever topology of a network changes, DSDV is unstable until update packets propagate through the network DSDV is effective for creating ad-hoc networks for small populations of mobile nodes DSDV is a fairly brute force approach, because connectivity information needs periodical update througout the whole network
44
V2V Network Protocols MANET – DSR (On-Demand)
On-demand route discovery DSDV is a proactive protocol: maintains all topology information DSR is a reactive protocol : maintains active routes Routes automatically determined and maintained No periodic packets => entirely on-demand E.g. Routing advertisement, Link status sensing, Neighbour detection packets Source routing sender of a packet determines the complete sequence of nodes to forward the packet No need to maintain information at intermediate nodes reaction to topology changes more rapid => node caches multiple routes to destination Avoids need to perform Route Discovery each time a route breaks
45
V2V Network Protocols MANET – DSR : main functions Route Discovery:
Allows any host to dynamically discover a route to any other host in the ad hoc network. A host initiating a route discovery broadcasts a route request packet Each route request packet contains a route record If successful, initiating host receives a route reply packet The route is saved in the cache for future use Route maintenance: Host monitors the correct operation of routes in use
46
V2V Network Protocols MANET – DSR : Route Discovery S A B E C F D G
When node S wants to send a packet to node D, but doesn’t know route to D, it initiates a route discovery Source node S floods Route Request (RREQ) Each node appends its own address when forwarding RREQ When node d receives RREQ it sends RREP to node S Duplicate RREQ are discarded S RREQ transmission A RREP transmission B Broadcast E C F D G
47
V2V Network Protocols RREP [S,A,B,C,D]
MANET – DSR : Route Reply (RREP) Route Reply (RREP) is sent by reversing the route in Route Request (RREQ) An intermediate node having a route to D can also send back a RREP RREP [S,A,B,C,D] S A RREP transmission B Broadcast E C F D G
48
V2V Network Protocols MANET – DSR : Advantages and disadvantages
Reactive: routes maintained only between nodes who need to communicate Route caching can reduce route discovery overhead Disadvantages Packet header size grows with route length due to source routing Flood of route requests may potentially reach all nodes in the network Care must be taken to avoid collisions between route requests and route reply propagated by neighboring nodes Route Reply Storm problem When a node sending RREP hears another RREP with a shorter route Route reply storms also prevented by randomising delay time before sending route replies
49
V2V Network Protocols MANET – AODV (Ad-hoc On-demand Distance Vector)
Designed for MANETs with 10,000 to 100,000 nodes Improves scalability and performance Reduces dissemination of control traffic Eliminates overhead on data traffic Uses a broadcast route discovery mechanism Every node maintains two separate counters Sequence number Broadcast-id (RREQ ID) Node sequence number ensures loop freedom Route’s “freshness” is decided by sequence numbers that each node maintains for all destinations in their routing table Only active routes are maintained
50
V2V Network Protocols MANET – AODV : Route Discovery
Route discovery is initiated by broadcasting RREQ When sender has no route to destination, or Route to destination is invalid or expired RREQ contains last known Dest Seq Num When an intermediate node receives a RREQ, it records a “reverse” distance vector back towards the source then broadcasts the RREQ to its neighbors A neighbor satisfies the RREQ sends a RREP back to the source If an intermediate node is a destination or has a route entry for the destination The route reply travels in the “reverse path” set up when the request packet was being forwarded
51
V2V Network Protocols MANET – AODV : Route Table
Route updated whenever node receives new information about the seq. num from RREQ, RREP or RERR route only updated if the dest seq num is either > dest. seq num in route table seq nums are equal, but the new hop count + 1 < existing hop count in the routing table Dest seq num is unknown. Lifetime = ACTIVE_ROUTE_TIMEOUT Route Table Entry Destination IP Address Destination Seq. Num Valid Destination Seq. Num field State and routing flags Network Interface Hop Count (# of hops to destination) Next Hop List of Precursors Lifetime
52
V2V Network Protocols Routing protocol Analysis for vehicle Ad-Hoc
requires protocol that can find path more faster for High-mobility Ad hoc Among nowadays routing protocols, on-demand method has more efficiency but require new routing protocol adopted on V2V environment
53
Projects and Standards
1 비넷에 과한 강의를 시작하겠습니다.
54
Projects and Standards
55
Projects and Standards
Services & Project (Korea) WISDOM WISDOM - Wireless Interface Signal control system for Dynamic and Optimal Management Real time signal control provide information and safety Black-Box based emergency service e-call ACN service U-Traffic related service UTIS (Urban Traffic Information System)
56
Projects and Standards
Standards (Korea) DSRC TTA ASK -> QPSK WAVE ETRI Planed to make a convergence among cellular and DMB, wireless lan, Advanced Short Range Communication (ADSRC) Planed to make international standard to provide high speed packet service for 5.8㎓~10㎒ can support handover Researching Broadband wireless LAN standards for 전파방송 기술위원회 (TC3) PG310 - ITS/Telematics CALM National Police headquarters - UTIS Wireless communication system for ITS Based on CALM Mobility : 180Km/h (max) Collect/provide Real time traffic information
57
Projects and Standards
C2C-C Consortium Industrial consortium (mostly) comprised of car manufacturers and electronics suppliers operating in Europe Primary goal: Defining a European standard for vehicular communication Aims at harmonizing with other bodies (e.g. ISO) to build an European infrastructure for ITS applications
58
Projects and Standards
Unit Architecture and C2C-CC WGs
Similar presentations
© 2025 SlidePlayer.com Inc.
All rights reserved.