WO2009132704A1

WO2009132704A1 - An indoor base station system

Info

Publication number: WO2009132704A1
Application number: PCT/EP2008/055305
Authority: WO
Inventors: Hans-Åke LUND; Ulf JÖNSSON
Original assignee: Telefonaktiebolaget Lm Ericsson (Publ)
Priority date: 2008-04-30
Filing date: 2008-04-30
Publication date: 2009-11-05

Abstract

The present invention relates to an indoor base station system, comprising an indoor base station (1 ), an external anchor point (7) and an external connection (9), the indoor base station (1 ) being connected to the external anchor point (7) via the external connection (9). The external anchor point (7) is arranged for routing data packet traffic to and from certain services provided and the external connection (9) is arranged for routing data packet traffic to and from broadband services. The system is arranged to set up a direct connection, a tunnel, between the indoor base station (1 ) and the external anchor point (7). Only data packet traffic that is desired to be handled by the anchor point (7) is forwarded via the tunnel (6), and all other data packet traffic is handled by the external connection (9), the forwarding being determined by means of forwarding policies. The present invention also relates to a corresponding method and anchor point.

Description

TITLE

An indoor base station system

TECHNICAL FIELD

The present invention relates to an indoor base station system, comprising an indoor base station, an external anchor point and an external connection, the indoor base station being connected to the external anchor point via the external connection, the external anchor point being arranged for routing data packet traffic to and from certain services provided and the external connection being arranged for routing data packet traffic to and from broadband services, the system being arranged to set up a direct connection, a tunnel, between the indoor base station and the external anchor point.

The present invention also relates to a method for forwarding data packet traffic messages from an indoor base station and an anchor point.

BACKGROUND

Today, communication both at home and elsewhere more and more takes place in the form of wireless communication. This of course stresses the present radio base stations which are used for relaying information to and from users. In order to acquire an enhanced indoor coverage, smaller indoor base stations are used. One type of such an indoor base station is a so- called Femto cell base station. A Femto cell base station is thus a small local radio base-station that normally is placed in residential or small business environments, supporting a relatively small number of users. A Femto cell base station enhances in- house coverage and lowers the radio network resource requirements on ordinary radio base stations, and is especially useful where access would otherwise be limited or unavailable.

While a user is at home, his or her mobile will be connected to the Femto cell base station, which will be connected to the operator via a residential broadband connection, using DSL (Digital Subscriber Line), fiber or other technologies.

A Femto cell base station may for example use any one of the known networks/standards GSM (Global System for Mobile communications), WCDMA (Wideband Code Division Multiple Access) or LTE (Long Term Evolution) for the radio technology.

In current implementations of Femto cell base stations, all traffic from the users mobile device being carried via the Femto cell base station, must be sent to and from a central anchor-point such as a node of the type GGSN (Gateway GPRS (General Packet Radio Service) Support Node) or a PDN- GW (Packet Data Network Gateway) before it is forwarded to the different services that a user wants to access. Such services comprise Internet, webservers, fileservers etc.

The type of node used depends on which radio technology that is used. For existing solutions, all traffic to and from connected Femto cell base stations is routed via the anchor point, the GGSN or PDN-GW, which means that high bandwidth broadband traffic always has to pass the anchor point. This of course constitutes a problem, since the anchor point's capacity will be a limiting factor for all the Femto cell base station traffic. Furthermore, this means that the traffic is transmitted an unnecessarily long route, which results in unnecessarily high transmission costs.

SUMMARY

The object of the present invention is to provide an indoor base station system, where the traffic load on anchor points is reduced, relieving anchor points of traffic load and reducing transmission costs.

Said problem is solved by an indoor base station system comprising an indoor base station, an external anchor point and an external connection. The indoor base station is connected to the external anchor point via the external connection, where the external anchor point is arranged for routing data packet traffic to and from certain services provided. The external connection is arranged for routing data packet traffic to and from broadband services. The system is arranged to set up a direct connection, a tunnel, between the indoor base station and the external anchor point.

Only data packet traffic that is desired to be handled by the anchor point is forwarded via the tunnel, and all other data packet traffic is handled by the external connection, the forwarding being determined by means of forwarding policies.

Said problem is also solved by a method for forwarding data packet traffic messages from an indoor base station. The method comprises the steps: - Determining if a data packet traffic message should be forwarded to an external anchor point, used for routing data packet traffic to and from certain services provided, or to an external connection, used for routing data packet traffic to and from broadband services.

- Routing the data packet traffic message either to the external anchor point via a direct connection, a tunnel, or to the external connection, depending on the outcome of the determining step.

Said problem is also solved by a an anchor point in an indoor base station system, which system further comprises an indoor base station, and an external connection. The indoor base station is connected to the external anchor point via the external connection, the external anchor point being arranged for routing data packet traffic to and from certain services provided and the external connection being arranged for routing data packet traffic to and from broadband services. The system is arranged to set up a direct connection, a tunnel, between the indoor base station and the external anchor point. Only data packet traffic that is desired to be handled by the anchor point is forwarded via the tunnel, and all other data packet traffic is handled by the external connection, the forwarding being determined by means of forwarding policies which are transmitted from the anchor point to the indoor base station via a tunnel.

According to an example of the invention, the indoor base station comprises a router arrangement for routing outgoing data packet traffic either to the external connection or to the anchor point.

According to another example of the invention, the forwarding policies comprise a list of Internet protocol, IP, addresses, which IP addresses determine which data packet traffic that should be forwarded to the anchor point . According to another example of the invention, a data packet traffic message that is intended to be forwarded to the anchor point via a tunnel is equipped with a certain IP tunnel head. The router arrangement may be arranged for adding said IP tunnel head to a data packet traffic message that is intended to be forwarded to the anchor point.

According to another example of the invention, the forwarding policies are transmitted from the anchor point to the indoor base station via a tunnel, for example a Gateway Tunnel Protocol, GTP, tunnel, where the GTP then is extended in order to carry out the present invention.

Other examples of the invention are disclosed in the dependent claims.

A number of advantages are obtained by means of the present invention. For example:

- It is possible to choose which traffic that is going to be routed via a central anchor point.

- If desired, broadband user traffic between a device at home and the external services may be routed directly via an external connection, and not via a central anchor point, enabling a user to obtain a faster service.

- The anchor point may be relieved of those traffic messages that do not have to pass via the anchor point.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will now be described more in detail with reference to the drawings, where Figure 1 shows a system configuration according to the present invention;

Figure 2a shows a first type of traffic message;

Figure 2b shows a second type of traffic message; and

Figure 3 shows a flowchart for a method according to the present invention.

DETAILED DESCRIPTION

In Figure 1 , a Femto cell base station is shown, being placed indoors. The Femto cell base station 1 is connected to a broadband connection 2 via a residential gateway 3, such as a broadband modem. A mobile phone 4 and a computer 5 are shown as examples of equipment that may communicate via the Femto cell base station 1.

When connected, the Femto cell base station 1 will, with normal 3GPP (3rd Generation Partnership Project) standardized methods, set-up a GTP (GPRS

Tunneling Protocol) tunnel connection 6 to a GGSN or Serving/PDN-GW i.e. an anchor point 7. The tunnel passes an access and backbone network 8, comprising the nearest internet connection point 9 in the operator's network.

This connection point 9 is commonly called Access Edge Router.

The Access Edge Router 9 is normally used for connecting the broadband user to his or hers ordinary broadband services, such as the Internet 10, via an ordinary connection 1 1 a, 1 1 b. The ordinary connection 11 a to the Access Edge Router 9 and the tunnel connection 6 seems to be physically different in Figure 1 , but between the residential gateway 3 and the Access Edge Router they are constituted by one and the same physical connection, and are drawn separately in order to increase the comprehension of the present invention.

In the following, when the term "traffic" is used, data packet traffic, i.e. transmission traffic comprising data packets, is meant.

When the tunnel connection 6, hereafter referred to as tunnel, is set up to the anchor point 7, the traffic between the Femto cell base station 1 and the anchor point 7 will pass directly between them, only passing via the Access Edge Router 9. The anchor point 7 routes traffic to and from certain services provided, such as TV 7a, web-servers 7b etc.

It is a basic concept of the present invention that all the traffic should not go to the anchor point 7, in particular if the destination of the traffic is placed close to the source of the traffic from a network topology view.

According to the present invention, as the tunnel 6 between the Femto cell base station 1 and the anchor point 7 is established, the forwarding policies in the Femto cell base station 1 will be controlled by the anchor point 7 such that only traffic that is desired to be handled by the anchor point 7 is forwarded via the tunnel 6. This means that such traffic, for example Internet traffic, which need not pass the anchor point 7, will not be transmitted via the tunnel 6; instead it is transmitted directly to the Internet 10 via the Access Edge Router 9. Thus broadband traffic, such as Internet traffic, will not have to pass via an anchor point 7 at all, relieving the anchor point 7 of that burden, thus increasing system capacity and reducing transmission costs. More in detail, traffic relating to services which an anchor point operator charges is directed to and from the anchor point 7 directly, via the Access Edge Router 9, by means of the tunnel 6. All other traffic is directed to and from the Access Edge Router 9 for further connection to other services 10, 12, such as the Internet 10. The traffic is bi-directional during a so-called session when it has been set up, i.e. when the initial traffic has been directed to the anchor point 7 or the Access Edge Router 9, the following traffic in the session is bi-directional. A session thus relates to traffic associated with the initial traffic, setting up the session. When the session ends, a new session will have to be set up, using the directing procedure according to the present invention.

Those services which the anchor point operator charges are listed in the form of IP (Internet Protocol) addresses or ranges of addresses, which list is transmitted from the anchor point 7 to the Femto cell base station 1. The list is dynamic, being updated when necessary or desired, and is re-sent to the Femto cell base station 1 at certain times. The list constitutes forwarding policies.

With reference to Figure 2a, a first type of a traffic message 13, in the form of a packet, which does not use a tunnel 6, comprises an IP head 14 and data 15, where the IP head 14 determines the destination of the data 15. In accordance with the present invention, such a traffic message 13 does thus not reach an anchor point 7.

With reference to Figure 2b, a second type of a traffic message 16 which does use a tunnel 6, comprises an IP head 17, similar to the one described with reference to Figure 2a, an IP tunnel head 18 and data 19. Thus, if an IP tunnel head 18 is present, the traffic message 16 will be sent directly to the anchor point 7 via the tunnel 6. This means that the Femto cell base station 1 suitably comprises a router arrangement 20 for routing an outgoing message either to the Access Edge Router 9 directly to other services 10, 12 or to the anchor point 7. If a traffic message 16 relates to a service which is present on the list, i.e. relates to a service which the anchor point operator charges, the router arrangement 20 adds an IP tunnel head 18 to the outgoing traffic message 16, otherwise it doesn't. As mentioned above, when a session has been set up, the traffic is bi-directional during that session.

In this way, payload traffic from and to user devices connected to the Femto cell base station 1 does not always has to go through a single point such as the GGSN or Serving/P DN-GW anchor points 7. For example, broadband user traffic between a device at home 4, 5 and the Internet 10 can go directly through the Access Edge Router 9, and not via the anchor point 7.

With reference also to Figure 3, the present invention also relates to a method for forwarding a traffic message 13, 16 from an indoor base station 1 , where the method comprises the steps: 21 : determining if the traffic message 13, 16 should be forwarded to an external anchor point 7, used for routing traffic to and from certain services provided, or an external connection 9, used for routing traffic to and from broadband services; and

22: routing the message either to the external anchor point 7 via a direct connection, a tunnel, or to the external connection 9, depending on the outcome of the determining step.

The invention is not limited to the embodiment described above, but may vary freely within the scope of the appended claims. For example, the actual contents of the forwarding policies may be configured in the anchor point 7 or sent to them from an external service policy server that in essence supplies a list of services, based on destination IP addresses or IP subnets, that has to be routed through the anchor point 7. The default should be that the user intends to use other services than those connected to the anchor point 7, for example the Internet.

The anchor point may be any suitable node, the GGSN or Serving/PDN-GW are mentioned as examples only.

In the example above, only one Femto cell base station 1 is shown, naturally there may be a number of Femto cell base stations 1 connected to each Access Edge Router 9 and anchor point 7.

The present invention is applicable to any suitable indoor base station, not only the one using Femto cell base stations.

The forwarding policies may be any form of controlling means, intended for directing messages a desired route. The fact that a message is routed to an anchor point does not necessarily mean that it is related to a service which the anchor point operator charges, but merely that the anchor point operator desires routing to take place, whatever the reason.

The router arrangement 20 is normally based on a standard routing functionality in the Femto cell base station 1 , where the forwarding policies may be constituted by a table of IP subnets and/or host routes to different destinations, where the table is stored in the Femto cell base station 1. The default setting is to send data packet traffic directly to the other services 10, 12. Any suitable protocol may be used for setting up the tunnel between the Femto cell base station 1 and the anchor point 7. The protocol, which originally is a basic protocol, has to be extended in order to handle the forwarding policies. If the GTP is used between the Femto cell base station 1 and the anchor point 7, the forwarding policies are sent from the anchor point 7, with extensions to the GTP protocol that is used, towards the Femto cell base station. The protocol used is then an extended GTP.

The actual format of the information elements for carrying the forwarding policies has to be extended from their original format. The extended format may for example be modeled according to a format that is described in the Internet standards track protocol RFC 3442; Classless Static Route Option for Dynamic Host Configuration Protocol (DHCP).

On the Internet, a so-called point-of presence (PoP) is an access point from one place to the rest of the Internet. By way of example, the PoP may be situated in the Access Edge Router. In a Femto cell base station system, PoP is primarily used for mobile phone traffic, where, in this invention, the broadband data packet traffic may be re-directed to another PoP, typically a PoP in the wire-bound telephone network.

Claims

1. An indoor base station system, comprising an indoor base station (1 ), an external anchor point (7) and an external connection (9), the indoor base station (1 ) being connected to the external anchor point (7) via the external connection (9), the external anchor point (7) being arranged for routing data packet traffic to and from certain services provided and the external connection (9) being arranged for routing data packet traffic to and from broadband services, the system being arranged to set up a direct connection, a tunnel (6), between the indoor base station (1) and the external anchor point (7), characterized in that only data packet traffic that is desired to be handled by the anchor point (7) is forwarded via the tunnel (6), and all other data packet traffic is handled by the external connection (9), the forwarding being determined by means of forwarding policies.

2. An indoor base station system according to claim 1 , characterized in that the indoor base station (1 ) comprises a router arrangement (20) for routing outgoing data packet traffic either to the external connection (9) or to the anchor point (7).

3. An indoor base station system according to any one of the previous claims, characterized in that the forwarding policies comprise a list of Internet protocol, IP, addresses, which IP addresses determine which data packet traffic that should be forwarded to the anchor point (7).

4. An indoor base station system according to claim 3, characterized in that a data packet traffic message (16) that is intended to be forwarded to the anchor point (7) via the tunnel (6) is equipped with a certain IP tunnel head (18).

5. An indoor base station system according to claim 4, characterized in that the router arrangement (20) is arranged for adding said IP tunnel head (18) to a data packet traffic message (16) that is intended to be forwarded to the anchor point (7).

6. An indoor base station system according to any one of the previous claims, characterized in that the forwarding policies are transmitted from the anchor point (7) to the indoor base station (1 ) via the tunnel (6).

7. An indoor base station system according to any one of the previous claims, characterized in that the anchor point (7) is a node of the type Gateway GPRS, General Packet Radio Service, Support Node, GGSN, or a Packet Data Network Gateway, PDN-GW.

8. An indoor base station system according to any one of the previous claims, characterized in that the indoor base station (1 ) is of the type Femto cell base station.

9. An indoor base station system according to any one of the previous claims, characterized in that the external connection (9) is an Internet external connection (9) of the type Access Edge Router.

10. An indoor base station system according to any one of the previous claims, characterized in that the protocol used for setting up the tunnel between the Femto cell base station 1 and the anchor point 7 is an extended Gateway Tunnel Protocol, GTP.

11. An indoor base station system according to any one of the previous claims, characterized in that the forwarding policies are extended, being modeled according to a format according to the Internet standards track protocol RFC 3442; Classless Static Route Option for Dynamic Host Configuration Protocol, DHCP.

12. A method for forwarding data packet traffic messages (13, 16) from an indoor base station (1 ), characterized in that the method comprises the steps:

(21 ) determining if a data packet traffic message (13, 16) should be forwarded to an external anchor point (7), used for routing data packet traffic to and from certain services provided, or to an external connection (9), used for routing data packet traffic to and from broadband services; and

(22) routing the data packet traffic message (13, 16) either to the external anchor point (7) via a direct connection, a tunnel, or to the external connection (9), depending on the outcome of the determining step.

13. A method according to claim 12, characterized in that only data packet traffic that is desired to be handled by the anchor point (7) is forwarded via the tunnel (6), and all other data packet traffic is forwarded to the external connection (9), the forwarding being determined by means of forwarding policies.

14. A method according to any one of the claims 12 or 13, characterized in that the forwarding policies use a list of Internet protocol, IP, addresses, which IP addresses determine which data packet traffic that should be forwarded to the anchor point (7).

15. A method according to any one of the claims 12-14, characterized in that a data packet traffic message (16) that is intended to be forwarded to the anchor point (7) via a tunnel (6) is equipped with a certain IP tunnel head (18).

16. A method according to any one of the claims 12-15, characterized in that a router arrangement (20) is used for adding said IP tunnel head (18) to a data packet traffic message (16) that is intended to be forwarded to the anchor point (7).

17. A method according to any one of the claims 12-16, characterized in that the protocol used for setting up the tunnel between the Femto cell base station 1 and the anchor point 7 is an extended Gateway Tunnel Protocol, GTP.

18. A method according to any one of the claims 12-17, characterized in that the forwarding policies are extended, being modeled according to a format according to the Internet standards track protocol RFC 3442; Classless Static Route Option for Dynamic Host Configuration Protocol, DHCP.

19. An anchor point (7) in an indoor base station system, which system further comprises an indoor base station (1 ), and an external connection (9), the indoor base station (1 ) being connected to the external anchor point (7) via the external connection (9), the external anchor point (7) being arranged for routing data packet traffic to and from certain services provided and the external connection (9) being arranged for routing data packet traffic to and from broadband services, the system being arranged to set up a direct connection, a tunnel, between the indoor base station (1 ) and the external anchor point (7), characterized in that only data packet traffic that is desired to be handled by the anchor point (7) is forwarded via the tunnel (6), and all other data packet traffic is handled by the external connection (9), the forwarding being determined by means of forwarding policies which are transmitted from the anchor point (7) to the indoor base station (1 ) via a tunnel (6).

20. An anchor point (7) according to claim 19, characterized in that it is a node of the type Gateway GPRS, General Packet Radio Service, Support Node, GGSN, or a Packet Data Network Gateway, PDN-GW.

21. An anchor point (7) according to any one of the previous claims 19-20, characterized in that the protocol used for setting up the tunnel between the Femto cell base station 1 and the anchor point 7 is an extended Gateway Tunnel Protocol, GTP.

22. An anchor point (7) according to any one of the previous claims 19-21 , characterized in that the forwarding policies are extended, being modeled according to a format according to the Internet standards track protocol RFC 3442; Classless Static Route Option for Dynamic Host Configuration Protocol, DHCP.