An Overview of the GeoNet BoF
GeoNet stands for geographical networking. The concept relates to the intertwining of Internet Protocol (IP) networking with geographical addressing. As used today, IP routing and addressing operate outside of geographic parameters such as coordinates or postal addresses. Possible applications of future Internet-wide geo-networking mechanisms include, but are not limited to, dissemination of IP packets to particular geographical areas, and precise tracking of package positions during a shipping process. More use cases are under discussion.
The Birds-of-a-Feather (BoF) meeting at IETF 88 was the result of a multiyear effort initiated in 2012 in the context of IP communications in vehicular networks. The initial email list is still being used despite a change in the name—it is hosted at https://www.ietf.org/mailman/listinfo/its and includes approximately 250 subscribers. We held a bar BoF at IETF 87 with the participation of some key contributors, including the chair of ETSI ITS WG3 “Networking and Transport,” and an IAB shepherd. After the publication of an initial set of Internet-Drafts, a request to meet as an official GeoNet BoF was approved by the IESG. More than 100 participants attended the Vancouver BoF meeting.
Current discussions target the development of a Charter and of a problem statement that will identify realistic goals for a potential working group. We also are refining a list of use cases around the topic of geographical dissemination of IP packets. While the first use case was related to vehicular communications (see below), more uses have been identified by partners at various organizations. The use case discussion is ongoing.
For the London meeting, the group is preparing a charter proposal that would briefly lay out the problem, list the use-cases, and develop a list of deliverables. See the current text at https://github.com/melindashore/geonet.
Earlier efforts in this area targeted vehicular communications with geonetworking as a potential side-product. Vehicular traffic efficiency and management improve traffic flow, traffic coordination, and traffic assistance, and provide up-to-date local information, maps, and relevant messages well-defined in space and time. This has obvious applications in ensuring traffic safety.
A fully functional mechanism for geographical dissemination of data to vehicles over IP networks would need the participation of many underlying mechanisms. Previous discussions revolved around the use of the DNS subsystem in the initial steps of resolving an IP address into a set of geocoordinates, and vice-versa. However, during the BoF meeting in Vancouver this was discarded based on certain drawbacks of a fully DNS-based architecture.
One aspect considered very early is related to IP-over-foo. In the context of vehicular communications several wireless link layers are used for exchanging data among vehicles—one is IEEE 802.11p, which makes use of spectrum in the 5.9GHz band. The particularly dynamic nature of vehicle movement leads to stringent requirements on the use of IP datagrams on these dynamic links, hence a potential activity ofIP-over-foo, in which foo equals 802.11p, has been identified. However, at this time, this topic seems dedicated solely to vehicular communications, rather than the generic problem of geographical dissemination of data across paths that may traverse the Internet. In addition, several groups of external Standards Development Organizations (e.g., IEEE P1609.3, ETSI ITS TC WG3, and ISO TC204 WG16) have already developed stack models that are in near-deployment phases.
Other interest has been expressed in vehicle-to-vehicle IP networking, alarm distribution among vehicles, vehicles in smart cities, autonomous driving, and more.
Mechanisms and IETF protocols are needed for authorized source nodes anywhere in the Internet to disseminate packets to other nodes in areas described by geographic parameters, while respecting the privacy concerns of sender and receiver. Parameters such as geographical coordinates and other geolocators, such as civic addresses, should be usable in order to specify the destination.
Privacy concerns need to guarantee from the start that the new dissemination mechanism cannot be used to identify the geographical situation of computers issuing requests to resources or to prevent access based on such supposed identification.
The main use cases currently under discussion are listed below. We expect that some will be merged to others or simply disappear. We will be meeting in London to discuss this.
- Dissemination to a geographical area (first figure): A source node, which may be located anywhere, sends packets to a wireless access router through the Internet. Those wireless access routers are selected based on geographical location information, and traffic is routed to them using the IPv6 address of the router and conventional IP routing. Each of the destination access routers then copies and broadcasts the received packets to listeners within its radio coverage area.
- Goods tracking (second figure). A good delivered by a shipping organization has a provider-independent IP address. This good is tracked in that its geographical position is known to end-users continuously throughout the entire delivery process. The IP address of the good is associated to the geographical coordinates of the router to which it connects. Using IP addresses enables very finely grained and precise tracking.
- Vehicular traffic safety, efficiency, management, and infotainment. The data disseminated to roadside units (RSUs) is relevant for traffic management and on-board infotainment.
- Mobile roadside unit. Most RSUs are placed at a fixed geographical location that will most likely not be changed until the device either reaches its end of life or is no longer needed at that location. But a mobile roadside unit, on the other hand, is portable and not switched off while moving, meaning that among other settings its geographical position adjusts as it moves. Such a mobile RSU allows more flexible use in multiple situations. For example, at a location along a road where there is ongoing road works, a road worker could take a Mobile RSU, position it somewhere at the road works site, and start sending warning messages to incoming vehicles. The next day it would position it elsewhere.
- Identification of originating area. In some IP network deployments in large cities, Internet Service Providers (ISPs) and Internet Content Providers (ICPs) need to identify which parts of the city originate the most IP traffic. When it has knowledge of the geographic location of an IP address, it can deduce the origin of the IP traffic and thus subsequently schedule its resources among the entire network to realize the best service for the Internet users.
- Geolocation of an instrumented ambulance. When an ambulance transports a casualty, the primary objectives are to get the medical data (e.g., vital signs) securely delivered to the hospital by telemetry through the Internet and to allow the Emergency Room doctor to remain connected to the emergency medical technicians in the ambulance. In addition, during this process the communication between the ambulance driver and the dispatcher, and the communication afforded by the ambulance hotspot to public authorities (Bring-Your-Own-Device, Bring-Your-Own-Communication), is critically qualified by geographical coordinates and geolocators such as civic addresses. This case should be further described because some of these functions are sometimes provided over radio by way of voice dispatching and by GPS trackers.
Relationships between GeoNet and other IETF Working Groups
Any new use cases GeoNet comes up with that require protocol changes for any overlay technology, such as LISP, can be done in the appropriate protocol working groups, such as the LISP WG.
The GEOPRIV working group concentrates on protocols that allow applications to represent location/geography objects and to allow users to express policies on how these representations are exposed and used. Moreover, GEOPRIV analyses the authorization, integrity, and privacy requirements that must be met when these representations of location/geography are created, stored, and used. GeoNet mainly focuses on how IP routing and addressing use such location/geography representations.
The LISP WG mainly focuses on network-layer-based protocol solutions that enable the separation of routing locators (where you are attached to the network) and identifiers (who you are) in one number space. GeoNet mainly focuses on how IP routing and addressing use geographic parameters to disseminate packets from a sender located anywhere in the Internet to nodes in the area specified by these geography parameters.
The ECRIT WG focuses on how location data and call routing information are used to enable communication between a user and a relevant emergency response center. In particular, the ECRIT WG has specified protocols to map emergency services identifiers and geodetic or civic location information to service contact URIs. GeoNet mainly focuses on how IP routing and addressing use location information to disseminate packets from a sender located anywhere in the Internet to nodes that are located in the area specified by this geodetic or civic location information.
The most important next steps are to refine the set of use cases to a subset of achievable goals and agree on a charter. We will be meeting in London to progress both.
The initial objectives of the group are focused on a common vocabulary for contexts using IP protocols and geography coordinates, on a data definition of geolocators, and on defining a bidirectional relationship—and not a mechanism—between geospatial locators and IP locators.
For a complete solution, many solutions at different layers would be needed for the items below:
- The accurate representation of geographic areas using coordinates such as geolocators/logical coordinates and geographical/physical coordinates, and for the naming of geographic areas.
- Ensuring that geographical area information (for example, geolocators, names, and physical geographic coordinates) is accurately mapped to an IP address or addresses.
- Databases associating locations with addresses may be maintained at the source, intermediate or edge nodes, and at specific IP locator nodes.
- Ensuring that an IP address can be accurately mapped to geographic area information (geolocators, names, and geographic physical coordinates). Note that this refers to the addresses of access routers, roadside units (RSUs), and so on, and not end nodes.
- Ensuring that data packets generated by source nodes placed arbitrarily in the Internet can be forwarded over multiple hops by using, where possible, geographic location representations of the destination node(s) and/or the intermediate nodes for the routing decisions, instead of using their IP addresses. Note that in order to solve the above challenge it is not mandated that all nodes located on the path from source to destination nodes are able to forward packets using the geocoordinates of the destination node(s) and/or the intermediate nodes for routing decisions. This is emphasized by using the words where possible.