Patent Application
20060149814
1. Technical Field
The present inventions relate to presence communications and, more particularly, relate to communications systems having presence awareness.
2. Description of the Related Art
Presence, availability and location (PAL) services require that a networked presence entity such as a presence server, is informed with information about the status of a device, application, or user. This information can be queried, polled, or pushed to watcher devices in order for the watchers to make intelligent decisions about when, where, and how to deliver information to the presence entity.
Presence and availability services are implemented in a basic form in some of the instant messaging applications available today. These programs allow a user to establish a “buddy list” of other users. When the user turns on the instant messaging application, he becomes “present”. If he has configured his client to do so, he is also indicated as “available”. However, he may change his presence and availability status depending if he goes off line, or becomes busy. If he has been idle for a period of time, the instant messaging client may automatically mark the user as idle.
The Internet Engineering Taskforce (IETF) as published some Requests for Comments (RFC) and an internet draft on presence used in Instant Messaging (IM) and the Session Initiation Protocol (SIP). M. Day, et. al. published “A Model for Presence and Instant Messaging,” Internet RFC 2778, in February 2000. M. Day, et. al. also published “Instant Messaging/Presence Protocol Requirements,” Internet RFC 2779, in February 2000. J. Rosenberg published “A Presence Event Package for the Session Initiation Protocol (SIP),” Internet draft draft-ietf-simple-presence-10.txt, on Jan. 31, 2003.
Currently presence, availability and location (PAL) services are mostly used to notify other users of a user's status. However, these capabilities are being enhanced to include device and application presence, as well as location services. For mobile users, location is a potentially beneficial enhancement.
The presence entity currently sends out messages to publish its presence status to the presence servers and watchers. What is needed is a more efficient way for a presence entity to make its presence status known.
An object of the present inventions is to provide amore efficient way for a presence entity to make its presence status known.
Another object of the present inventions is to provide a way for a presence entity to publish its presence status without creating additional network traffic.
A further object of the present inventions is to utilize knowledge already existing in network equipment and reduce presence demands on a presence entity.
An additional object of the present inventions is to utilize an access gateway to handle presence communications with a presence entity and a presence server.
A communications system is capable of knowing presence status of mobile communications devices such as cellular transceivers. An access gateway such as, for example, a PDSN access gateway or home agent access gateway, manages access to a mobile communications device. The access gateway knows the presence status of the mobile communications device and reports it to a presence server. For mobile IP the access gateway is either the PDSN or the home agent.
The access gateway can know the presence status using attributes obtained during management of system operation by the access gateway. The presence server receives the presence status for the mobile communications device without querying the mobile communications device. The access gateway may query the mobile communications device on a predetermined schedule to obtain presence status of the mobile communications device. The presence server can alternatively initiate a query of the access gateway for presence status of the mobile communications device, perhaps on a predetermined schedule. The access gateway knows the presence status of the mobile communications device by storing attributes from the mobile communications device. The access gateway can obtain presence data from a radio access network. The presence server receives the presence status for the mobile communications device by obtaining some of the attributes from the mobile communications device from the access gateway. The access gateway at a home network, known as a home agent, can hold attributes.
The details of the preferred embodiments and these and other objects and features of the inventions will be more readily understood from the following detailed description when read in conjunction with the accompanying drawings wherein:
The presence entity 110 communicates over an access protocol 150 with the presence aggregator 120, which according to the preferred embodiments is an access gateway. In the preferred embodiments, the presence aggregator 120 is an access device, such as a PDSN or a HA or a GGSN, but its function is not limited to these roles. A PDSN is a Packet Data Serving Node PDSN, a HA is a Home Agent and a GGSN is a GPRS (General Pack Data Service) Serving Node. The presence aggregator 120 may collect and publish presence status multiple presence servers 130.
By presence status in the present inventions, applicant means the status of one or more of the statuses selected from the group consisting of presence, availability and location (PAL). The presence, availability and location (PAL) statuses, with respect to a presence entity such as a mobile transceiver, can be defined as follows:
Note that the presence entity 110 may have control over which watcher 140 sees any of this information. For example, a presence entity 110 may allow only certain groups of watchers 140 to know its availability.
The presence aggregator 120 may also be a third party that publishes PAL information of the presence entity on its behalf.
The presence server 130 receives published information 160 from the presence aggregator 120, and stores this information in a local database. The presence server 130 can receive published information 160 from more than one presence aggregator 120. The presence server 130 also allows watchers 140 to request presence status of one or more presence entities 110. In other words, a watcher 140 can subscribe to the presence status of a device and the presence server 130 may notify the watcher when this status changes.
The presence server 130 may allow the presence entity 110 or the presence aggregator 120 to determine the privacy level of its PAL information. For example a presence entity 110 may be able to indicate to the presence server 130 that its entire presence status, or parts of its presence status, can be seen by only certain watchers 140. Then the presence server 130 must authenticate watchers 140 that request this presence status.
Watchers 140 can subscribe to the presence status of a presence entity 110 via the presence server 130. Several types of watchers 140 may exist. Subscribing watchers 140 subscribe 170 to the presence status of a presence entity 110 and then waits to be notified 180 of events by the presence server 130. Polling watchers 140, on the other hand, periodically request an update of the presence status of a presence entity 110. Polling watchers 140 are more efficient on wireless networks where bandwidth is limited and the watcher 140 wants some control over the volume of information sent.
Presence and availability services are considered for third generation cellular systems such as CDMA2000. The CDMA2000 system contains an access gateway known as the Packet Data Serving Node (PDSN) and defined in the CDMA2000 Wireless IP Standard, TIA/EIA IS-835-B, of September 2002.
There are two types of calls, simple IP and mobile IP. Simple IP calls follow path 280 and provide basic IP network access, with the mobile being assigned an IP address from the visited network. If a mobile using simple IP roams to a new RAN, it is likely to be assigned a different PDSN access gateway 240 and therefore assigned a new IP address, breaking any data transfer in progress. Mobile IP calls follow path 285 and allow an IP address to be assigned by a home network 290 and kept by a mobile device 210 as it roams across RANs. A mobile IP call will maintain application state and data transfer between handoffs, enhancing the overall user experience. Mobile IP calls are tunneled between the PDSN access gateway 240 and a home agent access gateway 291 using either IP-in-IP, GRE, or Ipsec.
Both simple IP and mobile IP types of calls are authenticated by the authentication, authorization and accounting (AAA) infrastructure, which consists of a foreign AAA (RADIUS FAAA) 252 and a home AM (RADIUS HAAA) 292. The user's profile and associated information resides in the RADIUS HAAA 292, so the RADIUS FAAA 252 proxies requests and responses between the PDSN access gateway 240 and the RADIUS HAAA 292. The home agent access gateway 291 may also communicate with the RADIUS HAAA 292 directly for a further round of authentication, if necessary, or to acquire an IP address for the mobile device 210.
Both simple IP and mobile IP calls connect to the internet 283. This is where a presence server 287 connects to obtain the presence information for either the simple IP or mobile IP access gateways. In the case of simple IP, the access gateway is the PDSN access gateway 240. In the case of mobile IP, the access gateway is made up of both the home agent 291 and the access gateway PDSN 240 acting together on the two sides of the mobile IP tunnel 285. Watchers 288 obtain presence status from the presence server 287 over the internet as well. The presence server 287 and the watchers 288 can alternatively be connected more directly to the simple IP or mobile IP data behind their respective PDSN access gateway 240 or home agent access gateway 291 for security or other reasons. An alternate connection is over the wide area network of the internet 283 as illustrated in the embodiment of
In the CDMA2000 network, a presence server 287 may exist either behind the PDSN access gateway 240, for simple IP, or behind the home agent access gateway 291, for mobile IP. Being in the core network would allow it to receive input from a number of presence entities as well as access gateways, such as the PDSN access gateway 240 and home agent access gateway 291. Presence capability is thus facilitated in the communications system of the present inventions by these access gateways. The presence status of a mobile device 210 is thus provided to the presence server 287 by facilitation of an access gateway thus improving network utilization.
While the embodiment of
Reporting of presence status in a CDMA2000 network may occur on the home agent access gateway 291 or the PDSN access gateway 240. We will discuss each case in detail. In CDMA2000, it may be useful to track presence status on behalf of a mobile device not only to enable communications to and from the mobile device, but to also gather detailed network usage statistics and track mobile node behavior for purposes of lawful electronic surveillance.
In the case of the home agent access gateway 291, the home agent access gateway may report presence status to the presence server 287 on behalf of a mobile device 210. The following attributes of presence status can be published at the presence server 287:
In general, the home agent access gateway may provide presence information on behalf of a mobile device based on any information that the home agent access gateway stores with respect to that mobile device. This includes the mobile IP mobility binding record (MBR), the AAA profile, and other information. We refer to the aggregate of information that the home agent access gateway can report to the presence server as the home agent access gateway (HA) Presence Data Record, or HA-PDR.
The home agent access gateway may update the presence server using at least two different methods: triggered updates and timer-based updates. Triggered updates are sent when the presence status of a presence entity such as a mobile device changes, for example, when a mobile device registers with the home agent access gateway. Timer based updates are sent periodically, and only include the changes in the presence status of all of the presence entities served by the home agent access gateway since the same update. Some combination of triggered and timer-based updates may be used.
The home agent access gateway may determine whether or not to transmit presence information on behalf of the mobile device depending on local configuration, or on attributes returned from the RADIUS HAAA.
In the case of the PDSN access gateway, the PDSN access gateway 240 may report the presence status to the presence server 287 on behalf of a mobile device 210. The following attributes of presence status can be published at the presence server 287:
In general, the PDSN access gateway 240 may provide presence status on behalf of a mobile device based on any information that the PDSN stores with respect to that mobile device. This includes any information received from the radio access network 230 over an A10/A11 interface, the AAA profile, and other information. Thus the access gateway efficiently provides presence status information to a presence server using the attributes already managed by the access gateway without additional network burden querying for or deriving that status information. We refer to the aggregate of information that the PDSN access gateway can report to the presence server as the PDSN Presence Data Record, or PDSN-PDR.
The PDSN access gateway may update the presence server using at least two different methods: triggered updates and timer-based updates. Triggered updates are sent when the presence status of a presence entity such as a mobile device changes, for example, when a mobile device registers with the PDSN. Timer based updates are sent periodically, and only include the changes in the presence status of all of the presence entities served by the PDSN since the same update.
The PDSN may determine whether or not to transmit presence information on behalf of the mobile depending on local configuration, or on attributes returned from the home AAA server.
When an access gateway 240 or 291 obtains the presence status of a mobile device 210, it will typically not need to query the mobile device 210. The presence status can be obtained by the access gateway from attributes within the access gateway or obtained from the Radio Access Network (RAN) 230.
Although the presence server receives the presence status for the mobile communications device without querying, the access gateway can query the mobile communications device on a predetermined schedule to obtain its presence status. This query can be initiated by the presence server or by the presence server in response to a request from a watcher. Alternatively this query of the access gateway for presence status of the mobile communications device can occur on a predetermined schedule.
Because the presence status of a user and the presence status of an application reside on a mobile communications device, the presence status of a mobile communications device can represent the status of the user using the device or the application on the device. The mobile communications device is the presence entity for devices, as well as users and applications.
Although the inventions have been described and illustrated in the above description and drawings, it is understood that this description is by example only, and that numerous changes and modifications can be made by those skilled in the art without departing from the true spirit and scope of the inventions. Although the examples in the drawings depict only example constructions and embodiments, alternate embodiments are available given the teachings of the present patent disclosure. For example, the inventions are applicable to wireless LAN or also wireline communications.
