METHOD AND SYSTEM FOR AN AUTOMATIC TRAFFIC OFFLOADING IN A WIRELESS TELECOMMUNICATION NETWORK WITH SON AND ANDSF CAPABILITIES

Abstract

Present invention refers to a method and a system for an automatic traffic offloading in a wireless telecommunication network with both Self Organization Network (SON) and Access Network Discovery and Selection Function (ANDSF) capabilities. According to various embodiments of the invention, a user equipment collects some status information and send said information to a node of the network, where an optimization algorithm is applied and a decision for an offloading through a Wi-Fi access point in range of the UE is taken.

Claims

1. A method for an automatic traffic offloading in a wireless telecommunication network with both Self Organization Network (SON) and Access Network Discovery and Selection Function (ANDSF) capabilities, the method is characterized by comprising the steps of: g) collecting both an ANDSF status and a Wi-Fi offloading status of a user equipment (UE); h) sending the collected statuses from the UE to a node of the wireless telecommunication network; i) applying, by the node, a SON optimization algorithm taking into account the collected statuses; j) if a Wi-Fi offloading is required based on the SON optimization algorithm, updating an UE offloading policy from an ANDSF server; k) checking whether the Wi-Fi offloading is allowed in the updated UE offloading policy; l) if Wi-Fi offloading is allowed, automatically traffic offloading, by the UE, through a Wi-Fi access point in range.

2. The method according to claim 1, wherein updating the UE offloading policy further comprising sending a message with a UE location, from the UE to the ANDSF server, and the policy server sending back to the UE the offloading policy according to the UE location.

3. The method according to claim 1, wherein more than one Wi-Fi access points are in the range of the UE, further comprising the step of selecting one of the Wi-Fi access points to perform an offloading.

4. The method according to claim 1 wherein each of the ANDSF status information and Wi-Fi offloading status comprising an ON state or an OFF state.

5. The method according to claim 1 wherein the wireless telecommunication network is a LTE network and the node is an e-Node B.

6. A system for an automatic traffic offloading in a wireless telecommunication network with both Self Organization Network (SON) and Access Network Discovery and Selection Function (ANDSF) capabilities, the system is characterized by comprising: a user equipment (UE) configured for collecting ANDSF statuses and Wi-Fi offloading statuses; sending the collected statuses to a node of the wireless telecommunication network; checking offloading policies received from a ANDSF server; and automatically traffic offloading through a Wi-Fi access point in range; an ANDSF server configured for updating UE offloading policies; a node configured for applying a SON optimization algorithm taking into account the statuses collected by the UE and sending indications for updating UE offloading policies.

7. The system of claim 6 wherein the wireless telecommunication network is a LTE network and the node is an e-node B.

8. A non-transitory computer readable medium embodying computer program code thereon for execution by a computer processor, wherein said computer program code includes instructions for causing an automatic traffic offloading performing the method according to claim 1.

Description

DESCRIPTION OF THE DRAWINGS

[0031] To complete the description that is being made and with the object of assisting in a better understanding of the characteristics of the invention, in accordance with a preferred example of practical embodiment thereof, accompanying said description as an integral part thereof, is a set of drawings wherein, by way of illustration and not restrictively, the following has been represented:

[0032] FIG. 1.shows a basic ANDSF architecture from prior art.

[0033] FIG. 2.shows a SON/ANDSF architecture according to one embodiment of the invention.

[0034] FIG. 3.shows a command flow for the ANDSF/SON interworking according to one embodiment of the invention.

[0035] FIG. 4.shows, according to one embodiment of the invention, an ADNSF/SON task flow.

[0036] FIG. 5.illustrates a particular embodiment of the present invention where Mobility Load Balancing (MLB) is improved by ANDSF Wi-FI offloading.

[0037] FIG. 6.illustrates a particular embodiment of the present invention where energy savings are improved by ANDSF Wi-Fi offloading.

DETAILED DESCRIPTION OF THE INVENTION

[0038] The invention describes a process for joining the ANDSF and SON architectures (the latter in its distributed configuration) to create a single common cooperation environment, where the SON elements are aware of the existence of Wi-Fi APs, without requiring being explicitly configured with this information, can trigger an UE offload to Wi-Fi when necessary and can take into account UE's Wi-Fi offload statuses for SON optimisation calculations.

[0039] FIG. 2 shows a SON/ANDSF architecture according to one embodiment of the invention. The UEs (14,15) regularly send updates to the SON enhanced e-Nodes B (21,22,23) about their ANDSF capabilities and Wi-Fi offload status, so that SON enhanced e-Nodes B can use it to refine and complement their SON optimisation algorithms, instructing UEs to perform Wi-Fi offloads if needed.

[0040] Therefore, two different functional blocks of functions can be considered in FIG. 2: [0041] A plugin, SON IF (71) deployed in the ANDSF Client (61) of the UEs which enables the UE to monitoring and sending information about its ANDSF capabilities, for example an ON state or an OFF state, and Wi-Fi offloading status to SON enhanced e-Nodes B (21,22,23), as well as being able to request a refresh of the ANDSF policies from an ANDSF server (41) (for example by performing a policy pull from the ANDSF server) and/or a Wi-Fi offload to a Wi-Fi AP (51) in the UE's range, by relying on the already existing ANDSF client, and when instructed by the SON enhanced e-Node B serving its cell. [0042] A module ANDSF IF (81) deployed inside the SON enhanced e-Nodes B, which collects the information about ANDSF capabilities and Wi-Fi offload statuses sent by the SON IF module of the UEs in the cell is serving the e-Node B. Feeding these pieces of information in its SON optimisation algorithms, so Wi-Fi offload capabilities in the UEs can be taken into account, and finally instructing the UEs to carry out ANDSF policy updates and/or Wi-Fi offloads if needed.

[0043] FIG. 3 represents a command flow for the ANDSF/SON interworking according to one embodiment of the invention, where periodically, the ANDSF IF module (81) deployed in the SON enhanced e-Node B (21) queries the UE, or more specifically the SON IF plugin (71) of the UE (14) in range for a report that collects the UE's current ANDSF status. After checking (2) and retrieving (3) this information from the ANDSF client (61), the SON IF plugin reports (4) the ANDSF status to the ADNSF IF, specifying at least the following two pieces of information: [0044] If the ANDSF support in the UE is on/off [0045] If the UE is currently offloading or not traffic to a Wi-Fi AP (51)

[0046] The SON optimization function in the e-Node B collects the information sent from all the UEs in range and thus assesses the overall status/health of the cell is serving. If a SON optimisation event is triggered after this analysis and it can be solved by launching a Wi-Fi offloading in a UE with ANDSF on (and not previously offloaded), the ANDSF IF instructs (5) the SON IF plugin in the selected UE(s) to update (6) its

[0047] ANDSF policies and check if Wi-Fi offload is feasible. Where it is possible, the sequence of commands is, according to one embodiment of the invention, as follows: [0048] the UE requests (7) an ANDSF policy update from the ANDSF client in the UE; [0049] the ANDSF application in the UE requests (7) an ANDSF policy update from the ANDSF server (41) specifying UE's current location (Cell ID, geographical coordinates); [0050] the ANDSF server sends (8) back the updated policies according to the UE's location to the ANDSF Client; [0051] if Wi-Fi offload is allowed and available in the policies retrieved from the ANDSF server, the ANDSF client commands the UE to check (9) (10) if Wi-FI offload is feasible (for example checking whether the Wi-Fi AP (51) is in range); [0052] if Wi-Fi offload is feasible, the ANDSF application reports (11) this circumstance to the SON IF, which updates (12) the UE status (offloaded) in the SON enhanced e-Node B, via its ANDSF IF; [0053] the UE offloads (13) its traffic to the selected Wi-FI AP;

[0054] FIG. 4 depicts, according to one embodiment of the invention, an ADNSF/SON task flow illustrating the main actions carried out by the two modules of a UE: ANDSF IF (81) and the SON IF (71), as well as their relationships and sequence. The reports (42) from the UE are received by the ANDSF IF. In the case of requiring an offloading (43), the SON IF will update (44) the policies according to the UE location. Then, if the offloading is allowed (45), the status will change to a to do state (46), otherwise it will keep an not possible state (47). The SON IF checks (48) the offloading until the offloading is completed, when the offloading status will be ready (49). Thus, according to the status of the UEs in the cell served by the e-Node B and their accomplished Wi-Fi offloads the SON optimisation function can adapt to the UE environment, deciding to switch off cells, adjust power and so on.

[0055] As explained before, present invention offers a simple straightforward solution for including new offloading possibilities, like Wi-Fi APs, into a SON enhanced mobile heterogeneous environment, thus expanding and complementing the number of optimisation choices available to a e-Node B serving a cell.

[0056] For illustrative purposes, a couple of particular embodiments focused on certain advantages are disclosed in detail in FIG. 5 (improving MLB) and FIG. 6 (Energy savings).

[0057] FIG. 5 illustrates a particular embodiment of the present invention where Mobility Load Balancing (MLB) is improved by ANDSF Wi-FI offloading. MLB is a functionality built into SON, which allows cells suffering from traffic congestion to transfer part of their load to other neighbouring cells, which have radio resources to spare. To perform this task, MLB requires neighbouring e-Nodes B to exchange information about load level and availability in the cells they are serving through the X2 interface, as well as information about the UEs attached to the involved e-Nodes B.

[0058] This particular embodiment of FIG. 5 represents two cells (52,53) (identified by their serving e-Node B A (54) and e-Node B B (55)) have been endowed with SON MLB capabilities and the SON/ANSDF interworking procedures of the present invention described before. At a precise moment, UE1 (56), UE2 (57) and UE3 (58) are attached to e-Node B A and both UE2 and UE3 start heavy downloads of data (for example video streaming or similar) that exhaust the radio resources at e-Node B A's disposal. The normal reaction of MLB would bet the transfer of UEs in the overlapping cell area from e-Node B A to e-Node B B in order to balance the load. However, if e-Node B is also heavily loaded by the UEs (59) served within his cell, the UE transfers will be rejected and both cells end up being congested and their attached UE experiencing QoS impairments.

[0059] If SON/ANDSF interworking capabilities are activated in UE2 and UE3, e-Node B A could fall back on ANDSF Wi-Fi offload to alleviate the congestion problems is experiencing. UE2 and UE3 will be then requested to perform a Wi-Fi offload, something that UE2 will disregard (no Wi-Fi AP in range) but UE3 would satisfy the request. Consequently, traffic overload in e-Node B A will be assuaged, without jeopardising QoS in e-Node B.

[0060] Therefore, it is achieved load balancing by seamlessly adding Wi-Fi APs located in the cell managed by a e-Node B as a valid offloading back-up choice to be activated in congestion situations.

[0061] FIG. 6 illustrates a particular embodiment of the present invention where energy savings are improved by ANDSF Wi-Fi offloading. SON energy saving functionalities are often optimized during night time switching off some of the cells, but this requires to increase the power other cells are emitting so total coverage is not jeopardised. This power increase is an expensive measure, whose cost could be cut back if UEs in the cell to be switched off could be previously detached and offloaded, to Wi-Fi AP for instance, making redundant the emission power increase in other cells. Given that during night time most of UEs remains static in residential areas with a home Wi-Fi AP in range, the SON/ANDSF integration described by present invention enables the emptying of cells, which can subsequently be switched off.

[0062] The example environment of FIG. 7 represents how, during daytime, e-Node B A (54) and e-Node B B (55) have a normal coverage, highlighted with a solid outline (52, 53), but during night time the SON energy saving functionality will try switching off one of them (B in this case), so UEs in that cell will be requested to transfer to e-Node B A's cell. To avoid coverage hole, the usual procedure requires e-Node B A to re-configure its emission parameters in order to cover A+B cell areas, as is highlighted by dashed line (60), with the consequent increase in energy consumptions. But, in this case, present invention could help to maintain overall coverage without increasing energy consumptions by instructing the UEs located in the area covered by e-Node B B to perform a Wi-Fi offload. Since during night time, most of the UEs are normally static and close to their home Wi-Fi APs (61), most off will be successfully accomplished, and therefore, once the cell has been emptied, e-Node B B can be switched off without the e-Node B A being forced to increase its coverage area, or at least not to the full extent of the joint A and B areas.

[0063] Therefore, emission power levels can be dynamically adjusted by complementing SON with ANDSF Wi-Fi offload functions, and even greater energy savings achieved.