Mobile Ad hoc Networking (MANET) J. Haerri Internet-Draft C. Bonnet Intended status: Experimental F. Filali Expires: August 29, 2007 Institut Eurecom, France February 25, 2007 MANET Position and Mobility Signaling: Problem Statement draft-haerri-manet-position-problem-statement-00 Status of this Memo By submitting this Internet-Draft, each author represents that any applicable patent or other IPR claims of which he or she is aware have been or will be disclosed, and any of which he or she becomes aware will be disclosed, in accordance with Section 6 of BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet- Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire on August 29, 2007. Copyright Notice Copyright (C) The IETF Trust (2007). Haerri, et al. Expires August 29, 2007 [Page 1] Internet-Draft Position Signaling: Problem Statement February 2007 Abstract This document contains a problem statement and justification for position and mobility signaling in MANET protocols. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 3. Use Cases . . . . . . . . . . . . . . . . . . . . . . . . . . 6 3.1. Vehicular Ad Hoc Networks . . . . . . . . . . . . . . . . 6 3.2. Wireless Sensor Networks . . . . . . . . . . . . . . . . . 6 3.3. Mobile Wireless Networks . . . . . . . . . . . . . . . . . 7 4. Requirements . . . . . . . . . . . . . . . . . . . . . . . . . 8 5. Problem Statement . . . . . . . . . . . . . . . . . . . . . . 9 5.1. Geographical Routing Protocols . . . . . . . . . . . . . . 9 5.2. Routes and Links Instability . . . . . . . . . . . . . . . 9 6. Approach Rationals . . . . . . . . . . . . . . . . . . . . . . 11 6.1. Geographical Routing Protocols . . . . . . . . . . . . . . 11 6.2. Routes and Links Instability . . . . . . . . . . . . . . . 11 7. IANA considerations . . . . . . . . . . . . . . . . . . . . . 12 8. Security considerations . . . . . . . . . . . . . . . . . . . 13 9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 14 9.1. Normative References . . . . . . . . . . . . . . . . . . . 14 9.2. Informative References . . . . . . . . . . . . . . . . . . 14 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 15 Intellectual Property and Copyright Statements . . . . . . . . . . 16 Haerri, et al. Expires August 29, 2007 [Page 2] Internet-Draft Position Signaling: Problem Statement February 2007 1. Introduction In recent months, a growing interest has been observed in position information for improving routing in mobile ad hoc networks, by trying to improve links stability, periodic maintenance, power consumption or even security. Indeed, by peeking into the recent litterature, we see that between 2004 and 2006, 3 IEEE transactions and 38 IEEE conference proceedings are related to mobility predictions, while ACM published 11 papers. The common point of all these new directions is the requirement of mobile nodes' mobility information. Some proposals need nodes velocity, others moving directions, or nodes position. The most complex ones require nodes position and velocity in order to extract mobility prediction patterns. The Intelligent Vehicule Community already understood the benefits safety provisionings could obtain from proactive visions as they started standardizing the information cars should share. For example, the VII consortium (Vehicle Infrastructure Integration) is standardizing the information that should be transmitted between vehicles. As routing protocols and eventually internet will come on top of intervehicular communications, a similar and possible collaborative approach should be undergone within the IETF. However, we do not know yet what kind of information are required to be transmitted, and it is quite clear that the community might not even all agree on a common framework. The aim of this document is to describe new orientations in network research that includes localization information and for what purpose such information is necessary. This document also discusses possible improvements on regular standardized MANET protocol with the help of mobility information, and point out possible application beyond the scope of MANETs. Haerri, et al. Expires August 29, 2007 [Page 3] Internet-Draft Position Signaling: Problem Statement February 2007 2. Terminology The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119]. Additionally, this document introduces the following terminology GPS - Global Positioning System. A geolocalization system developped and operated by the US Department of Defense that is able to provide accurate worldwide coordinates of devices equiped with GPS receivers. A similar European system is currently under developpement under the name of Galileo. The GPS system does not work without a clear access to at least 3 satellites, thus is inoperable for indoor positioning. GPS-free Positioning - A set of techniques that has been developped in order to provide a mean of localization in situation when a clear access to satellites is not possible. Most of the methods use multilateration techniques and require either a formal training, or an anchor node that knows its accurate position. Time - The universal GPS time expressed in seconds. Longitude - The longitude describes the location of a place on Earth east or west of a north-south line called the Prime Meridian located in Greenwich, UK. Longitude is given as an angular measurement ranging from 0 degree at the Prime Meridian to +180 degree eastward and -180 degree westward. Latitude - The latitude gives the location of a place on Earth north or south of the equator. Latitude is an angular measurement ranging from 0 degree at the Equator to 90 degree at the poles. Elevation - The elevation is the altitude of an object from a known level or datum. Common datums are mean sea level and the surface of the WGS-84 geoid, used by GPS. Azimuth - Azimuth is the horizontal component of a direction, measured around the horizon, from the north toward the east in the northern hemisphere, and from the south toward the west in the southern hemisphere. Mobility - mobility information related to a specific address, which MAY consist of a longitude, latitude and elevation, a velocity, an azimuth, or the time this mobility information has been sampled. Haerri, et al. Expires August 29, 2007 [Page 4] Internet-Draft Position Signaling: Problem Statement February 2007 Stability - a measure of the similarity between a node's sampled (past) mobility parameters and the actual ones. VANET - Vehicular Ad Hoc Networks. A particular set of MANET where cars and road infrastructures are equiped with wireless devices. Haerri, et al. Expires August 29, 2007 [Page 5] Internet-Draft Position Signaling: Problem Statement February 2007 3. Use Cases 3.1. Vehicular Ad Hoc Networks A vehicular ad hoc network (VANET) is a specific case of mobile ad hoc networks, where vehicules and road infrastructures are equiped with wireless devices. Accordingly, the vehicles are able to communicate with each other as well as interacting with the road infrastructure. One straightforward application of VANETs is safety, where communications are exchanged in order to improve the driver's responsiveness and safety in case of road incidents. A Vehicular ad hoc network is set up between cars and between cars and road infrastructures. Due to the increased mobility, basic MANET routing protocols are inefficient. Novel approaches have been suggested such as state-less geographical routing, where packets are routed without any specific route setup in the direction of the maximum progress toward the destination node. This class of routing protocols require the knowedge of, at least, the destination and the forwarding node positions. Most of them use GPS-provided coordinates. In order to obtain a routing decision, nodes MUST exchange position data by means of level 3 messages between cars, road infrastructures, and location servers. 3.2. Wireless Sensor Networks A Wireless Sensor Network (WSN) is an extreme form of a MANET in terms of the amount of devices and of their highly limited capabilities. Sensors can be low cost, mass produced devices operating for years on a pair of AAA batteries. A sensor dust can be spread over a monitored location, and from that moment on, the sensors are fixed and operate for the lifetime of their batteries, which are their most critical resource. Around a Sensor Network, sinks are deployed in order to collect the measurements from the sensors and relay the commands from the controllers. Thus, sensors automatically form a structure to forward unicast packets from the sensors to the sinks, and to propagate broadcast packets across the network from the sinks. In order to establish a routing infrastructure and scale to a large geographic area, sensors can be deployed to form a tree, a mesh or any kind of distributed graph that aims at optimizing communication and energy consumption. As sensor may only be aware of their own location, in order to Haerri, et al. Expires August 29, 2007 [Page 6] Internet-Draft Position Signaling: Problem Statement February 2007 improve the creation of a routing topology, position information MAY be exchanged between sensors and sinks. Moreover, as a mean of improving the detection and localization of a device moving in a monitored area, sensors MAY also have to exchanged location or mobility information between each others. 3.3. Mobile Wireless Networks A Mobile Wireless Network is a network where at least a group of nodes are mobile. A Mobile Wireless Network includes infrastructure and ad-hoc networks, VANETs, WSN, or Mesh Networks. The mobility of routers or clients involved in a Mobile Wireless Network is a major source of burden in standard routing protocols, including hand-overs, route errors, and reduced capacity. In order to improve this issue, mobility MAY be predicted to some extends, which could then be used to improve ressource management techniques and Quality of Service. In order to predict routers and clients' mobility and thus adapt the network topology, nodes MUST exchange at least velocity information, but SHOULD also obtain and share some means of positioning techniques, either GPS or other GPS-free systems. Haerri, et al. Expires August 29, 2007 [Page 7] Internet-Draft Position Signaling: Problem Statement February 2007 4. Requirements MANET Position and Mobility Signaling has the following requirements R1: All nodes requirering position information SHOULD be equipped with GPS devices. That will allow the network to have a synchronized time as well as position information. R2: Location signaling MUST be compatible with non-location signaling format, more specifically, the generalized packet/ message format [PacketBB] Haerri, et al. Expires August 29, 2007 [Page 8] Internet-Draft Position Signaling: Problem Statement February 2007 5. Problem Statement All protocols standardized, or currently in the process of being standardized, do not make any assumption on a positioning system, which could provide a mean of knowing neighboring nodes' coordinates and mobility. A node ID is the major (sometimes the only) source of information about other nodes. Whereas those protocols have been designed to work perfectly well without this kind of strong assumption, a growing popularity appeared in the community for location-enhanced protocols. The MANET Position and Mobility Signaling Format is possibility related to the following working groups: o Existing Routing Protocols (MANET, OSPF) o Network Mobility Support (NEMO) 5.1. Geographical Routing Protocols Moreover, the Manet working group within the IETF decided to standardize two well known protocols, AODV and OLSR. AODV is a reactive protocol, which opens a route on the specific request from a source node. On the other hand, OLSR is a proactive, also called table-driven protocol, which computes all possible routes from and to any reachable destination. In that perspective, the IETF is providing the community with two sets of protocols for different applications, possiblity working together in hybrid configurations. However, in recent years, a new class of routing protocol appeared. Geographical Routing Protocols, also called Geographical Fowarding Protocols as no formal routing techniques are considered, choose the forwarder based on the "best" progress towards a destination node. The "best" progess is not only the maximum progress, but includes a set of heuristics that chooses the optimal forwarder based on positions, directions, local density, or even interference. The common point in all those techniques is that they guarantee packet correct delivery and rely on the knowledge of the destination and the potential forwarder's locations. 5.2. Routes and Links Instability In the Mobile Ad Hoc Network community, the major source of instability in the provided protocols comes from nodes mobility. OLSR uses periodic topology maintenance, and AODV developped local route breaches repairing techniques. Moreover, any kind of optimization based on a fixed topology (even related to a large set Haerri, et al. Expires August 29, 2007 [Page 9] Internet-Draft Position Signaling: Problem Statement February 2007 of nodes), needs to be run again after a couple of seconds when nodes are moving. However, although those techniques may be appropriate for low mobility networks, they reach their limit when local mobility is sudden or lacks any correlation with the neighboring nodes. That is indeed not a surprise if Geographical Forwarding protocols became popular in Vehicular ad hoc networks, where maintaining even a single open route (not mentionning a set of routing tables) is often impossible. In order to solve this issue, a growing popularity came from mobility prediction techniques used as means to not only choose the best "actual" forwarder, but the best actual AND future forwarder that will reduce the maintenance burden. Similarly to Geographical Forwarding Protocols, the common points in all mobility predictions techniques is a node's access to its own location and a method to spread it to neighoring nodes. Mobility Predictions has been widely successfully studied in the last three years, from reactive to proactive approaches even to geographical routing protocols. Haerri, et al. Expires August 29, 2007 [Page 10] Internet-Draft Position Signaling: Problem Statement February 2007 6. Approach Rationals MANET Position and Mobility Signaling aims at extending Generalized MANET Packet/Message Format [PacketBB] to define a standardized packet format to exchange position and mobility information, and to improve the stability of Manet routing protocols. This section covers the rationale behind this approach. 6.1. Geographical Routing Protocols There is a large source of litterature on Geographic Routing Protocols. The most widely known is the Greedy Perimeter Stateless Routing [GPSR] protocol. The major source of burden in geographical forwarding techniques is to avoid falling into local maxima, which is when a node cannot find any neighbor providing a better progress than itself to the destination. In that case, one has to define backoff techniques, which guarantee to leave the local maximum at a cost of local detours. This is not the purpose of this paper to be exhaustive on all geographical routing protocols developped so far. The German project Networks on Wheels (NoW) [NoW] has been studying and improving this approach on Vehicular Ad Hoc Networks for the last 3 years and could be a good starting point. 6.2. Routes and Links Instability It has been shown that a simple single order mobility prediction model was able to deliver superior routing performances than DSR or AODV [AGAR]. A similar study has been extended to location services [KUMAR]. The conclusions were quite similar, by noticing that the diffusion of predicted future locations of nodes in the network could improve the performances of location services. On the other side of the routing techniques, different groups developped mobility prediction techniques in order to improve proactive protocols. It has been shown that the choice by OLSR of nodes moving in similar direction could improve its performance [MOLSR]. Moreover, an appropriate choice of Multipoint Relays based on actual and the predicted future topology configuration could significantly improve the MPR protocol, and accordingly, OLSR [KMPR]. Haerri, et al. Expires August 29, 2007 [Page 11] Internet-Draft Position Signaling: Problem Statement February 2007 7. IANA considerations This document does not require any IANA action. Haerri, et al. Expires August 29, 2007 [Page 12] Internet-Draft Position Signaling: Problem Statement February 2007 8. Security considerations This document is a problem statement and does not create any security threat. It discusses the concepts of the use of Position and Mobility information in Mobile Ad Hoc Networks. Haerri, et al. Expires August 29, 2007 [Page 13] Internet-Draft Position Signaling: Problem Statement February 2007 9. References 9.1. Normative References [PacketBB] Clausen, T., "Generalized MANET Packet/Message Format", < www.ietf.org/internet-drafts/ draft-ietf-manet-packetbb-03.txt>. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. 9.2. Informative References [AGAR] Agarwal, A. and S. Das, "Dead Reckoning in Mobile Ad-Hoc Networks", IEEE WCNC 2003, the 2003 IEEE Wireless Communications and Networking Conference, March 2003. [GPSR] Karp, B., "Greedy Perimeter Stateless Routing (GPSR)", . [KMPR] Harri, J., Filali, F., and C. Bonnet, "On the application of mobility predictions to multipoint relaying in MANETs: kinetic multipoint relays", AINTEC 2005, Asian Internet Engineering Conference, December 2005. [KUMAR] Kumar, V. and S. Das, "Performance of Dead Reckoning-Based Location Service for Mobile Ad Hoc Networks", IEEE Wireless Communications and Mobile Computing Journal, March 2004. [MOLSR] Menouar, H., Leonardi, M., and F. Filali, "A movement prediction-based routing protocol for vehicle-to-vehicle communications", V2VCOM 2005, 1st International Vehicle- to-Vehicle Communications Workshop, July 2005. [NoW] "Networks On Wheels (NoW)", . Haerri, et al. Expires August 29, 2007 [Page 14] Internet-Draft Position Signaling: Problem Statement February 2007 Authors' Addresses Jerome Haerri Institut Eurecom, France Phone: +33 4 93 00 8176 Email: haerri@eurecom.fr Christian Bonnet Institut Eurecom, France Phone: +33 4 93 00 8108 Email: bonnet@eurecom.fr Fethi Filali Institut Eurecom, France Phone: +33 4 93 00 8134 Email: filali@eurecom.fr Haerri, et al. Expires August 29, 2007 [Page 15] Internet-Draft Position Signaling: Problem Statement February 2007 Full Copyright Statement Copyright (C) The IETF Trust (2007). This document is subject to the rights, licenses and restrictions contained in BCP 78, and except as set forth therein, the authors retain all their rights. This document and the information contained herein are provided on an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Intellectual Property The IETF takes no position regarding the validity or scope of any Intellectual Property Rights or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; nor does it represent that it has made any independent effort to identify any such rights. Information on the procedures with respect to rights in RFC documents can be found in BCP 78 and BCP 79. Copies of IPR disclosures made to the IETF Secretariat and any assurances of licenses to be made available, or the result of an attempt made to obtain a general license or permission for the use of such proprietary rights by implementers or users of this specification can be obtained from the IETF on-line IPR repository at http://www.ietf.org/ipr. The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights that may cover technology that may be required to implement this standard. Please address the information to the IETF at ietf-ipr@ietf.org. Acknowledgment Funding for the RFC Editor function is provided by the IETF Administrative Support Activity (IASA). Haerri, et al. Expires August 29, 2007 [Page 16]