WO2011026525A1

WO2011026525A1 - Analysis of connection errors and initiation of connection signaling minitoring between an user equipment and the communication network

Info

Publication number: WO2011026525A1
Application number: PCT/EP2009/061519
Authority: WO
Inventors: Petri Aalto; Juha Rontu
Original assignee: Nokia Siemens Networks Oy
Priority date: 2009-09-07
Filing date: 2009-09-07
Publication date: 2011-03-10

Abstract

An apparatus and a method are provided. The provided solution comprises a controller configured to monitor (201) call management errors occurring on connections between user equipment and a communication network; determine (202) a subscriber specific performance index for each connection of a subscriber; compare (204) the performance index of a subscriber to a preset threshold value; and initiate (206) monitoring of subscriber specific signaling of subscriber's connections if the performance index is greater than the preset threshold.

Description

ANALYSIS OF CONNECTION ERRORS AND INITIATION OF CONNECTION SIGNALING MINITORING BETWEEN AN USER EQUIPMENT AND THE COMMUNICATION NETWORK

Field

The embodiments of the invention relate generally to communication networks and, more particularly, to an apparatus and a method in communication networks.

Background

The following description of background art may include insights, discoveries, understandings or disclosures, or associations together with disclosures not known to the relevant art prior to the present invention but provided by the invention. Some such contributions of the invention may be specifically pointed out below, whereas other such contributions of the invention will be apparent from their context.

In communication networks, network planning is important to achieve good network quality and performance. Users of the networks expect that connections are set up fast and that the connections are reliable. Traffic volumes in communication networks are increasing and although generic network performance may be on a predicted level, some users may experience various quality problems.

The problems that single subscribers suffer may relate to failed call setup, dropping calls and bad throughput, for example. The subscribers complain about these events to operators. However, the operators do not have any detailed means of explaining what has happened.

Brief description

The following presents a simplified summary of the invention in order to provide a basic understanding of some aspects of the invention. This summary is not an extensive overview of the invention. It is not intended to identify key/critical elements of the invention or to delineate the scope of the invention. Its sole purpose is to present some concepts of the invention in a simplified form as a prelude to the more detailed description that is presented later.

According to an aspect of the present invention, there is provided an apparatus comprising a controller configured to monitor call management errors occurring on connections between user equipment and a communication network; determine a subscriber specific performance index for each connection of a subscriber; compare the performance index of a subscriber to a preset threshold value; and initiate monitoring of subscriber specific signaling of subscriber's connections if the performance index is greater than the preset threshold.

The apparatus may be configured to utilize a set of counters to count the number of different errors occurred on a connection, determine one or more performance indexes on the basis of the counters, and compare the values of the indexes to one or more preset thresholds.

The apparatus may be configured to store subscriber specific signaling of connections between user equipment and a communication network for a predetermined time and monitor the stored data on the basis of the subscriber specific performance index.

The apparatus may be configured to initiate the transmission of a message to a user of the connection, the message notifying the user that errors in the connections have been detected.

According to another aspect of the present invention, there is provided a method comprising: monitoring call management errors occurring on connections between user equipment and a communication network; determining a subscriber specific performance index for each connection of a subscriber; comparing the performance index of a subscriber to a preset threshold value; and initiating monitoring of subscriber specific signaling of subscriber's connections if the performance index is greater than the preset threshold.

A chipset may comprise the apparatus discussed above.

According to another aspect of the present invention, there is provided a computer program comprising program code means adapted to perform the method discussed above.

According to another aspect of the present invention, there is provided an article of manufacture comprising a computer readable medium and embodying program instructions executable by a computer operably coupled to a memory which, when executed by the computer, perform the method discussed above.

According to another aspect of the present invention, there is provided an apparatus comprising means for monitoring call management errors occurring on connections between user equipment and a communication network; means for determining a subscriber specific performance index for each connection of a subscriber; means for comparing the performance index of a subscriber to a preset threshold value; and means for initiating monitoring of subscriber specific signaling of subscriber's connections if the performance index is greater than the preset threshold.

Although the various aspects, embodiments and features of the invention are recited independently, it should be appreciated that all combinations of the various aspects, embodiments and features of the invention are possible and within the scope of the present invention as claimed.

List of drawings

Embodiments of the present invention are described below, by way of example only, with reference to the accompanying drawings, in which

Figure 1 illustrates an example of a communication network to which embodiments of the invention may be applied;

Figures 2A, 2B and 2C are flowcharts illustrating some embodiments of the invention;

Figure 3 is a signalling chart illustrating some embodiments of the invention; and

Figure 4 is a simplified example of an apparatus.

Description of embodiments

Exemplary embodiments of the present invention will now be described more fully with reference to the accompanying drawings, in which some, but not all embodiments of the invention are shown. Indeed, the invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Although the specification may refer to "an", "one", or "some" embodiment(s) in several locations, this does not necessarily mean that each such reference is to the same embodiment(s), or that the feature only applies to a single embodiment. Single features of different embodiments may also be combined to provide other embodiments. Like reference numerals refer to like elements throughout.

Embodiments are applicable to any base station, user equipment, server, corresponding component, and/or to any communication network or any combination of different communication networks that support required functionality.

The protocols used, the specifications of communication networks, servers and user terminals, especially in wireless communication, develop rapidly. Such development may require extra changes to an embodiment. Therefore, all words and expressions should be interpreted broadly and they are intended to illustrate, not to restrict, embodiments.

In the following, different embodiments will be described using, as an example of a system architecture to which the embodiments may be applied, an architecture based on UMTS terrestrial radio access (UTRA, UMTS = Universal Mobile Telecommunications System) without restricting the embodiment to such an architecture, however.

Many different radio protocols to be used in communications systems exist. Some examples of different communication systems are the universal mobile telecommunications system (UMTS) radio access network (UTRAN or E-UTRAN), long term evolution (LTE, known also as E-UTRA), long term evolution advanced (LTE-A) and GSM (Global System for Mobile Communication).

Figure 1 illustrates a simplified network architecture only showing some elements and functional entities, all being logical units whose implementation may differ from what is shown. The connections shown in Figure 1 are logical connections; the actual physical connections may be different. It is apparent to a person skilled in the art that the networks also comprise other functions and structures.

Figure 1 shows four base stations or NodeBs 100, 102, 104, 106 with coverage areas 100A, 102A, 104A and 106A, correspondingly. Base stations 100 and 102 are connected via an interface lub to a radio network controller 108. Base stations 104 and 106 are connected via an interface lub to a radio network controller 1 10. The radio network controllers 108, 1 10 may be connected to each other via an interface lur. The radio network controllers and base stations form a radio access network (RAN).

The communication network may further comprise a core network which may be divided into a circuit switched part 1 12 and a packet switched part 1 14. The radio network controllers 108, 1 10 may be connected to the circuit switched part 1 12 of the core network via an interface lu-CS and the packet switched part 1 14 via an interface lu-PS. Figure 1 shows three pieces of user equipment 1 16, 1 18, and 120. The user equipment 1 16 is in the coverage area 100A of the base station 100. The user equipment 1 18 is in the coverage area 104A of the base station 104 and the user equipment 120 is in the coverage area 106A of the base station 106. In the example of Figure 1 , the user equipment 1 16 is in an idle state and has a signalling connection 121 to a network, the user equipment 1 18 has an ongoing speech call 122 and the user equipment 124 has an ongoing data connection to the network. The user equipment refers to a portable computing device. Such computing devices include wireless mobile communication devices operating with or without a subscriber identification module (SIM), including, but not limited to, the following types of devices: mobile phone, smartphone, personal digital assistant (PDA), handset, laptop computer.

Figure 1 illustrates only a simplified example. In practice, the network may include more base stations and radio network controllers, and more cells may be formed by the base stations. The networks of two or more operators may overlap, the sizes and form of the cells may vary from that depicted in Figure 1 , etc.

It should be appreciated that the base stations or node Bs may also be connectable to a core network elements directly (not shown in the Figure). Depending on the system, the counterpart on the core network side can be a mobile services switching centre (MSC), a media gateway (MGW) or a serving GPRS (general packet radio service) support node (SGSN), home node B gateway (HNB-GW), mobility management entity and enhanced packet core gateway (MME/EPC-GW), etc. Also a direct communication between different node Bs over the air interface is possible by implementing a relay node concept, wherein a relay node may be considered as a special node B having wireless backhauls or, e.g., X2 and S1 interfaces relayed over the air interface by another node B. The communication system is also able to communicate with other networks, such as a public switched telephone network.

The embodiments are not, however, restricted to the network given above as an example but a person skilled in the art may apply the solution to other communication networks provided with the necessary properties.

In this application, embodiments will be described in conjunction with cellular communications systems. However, it should be understood that the embodiments may be utilized in several kinds of systems, both wired and wireless. In a typical communication network, the network elements including user equipment send each other signalling messages. The signalling messages may relate to current operations, such as ongoing connections or they may relate to system maintenance and other issues. For example, call set up procedures involve significant messaging between different network elements from the user equipment to the core network. Maintenance of ongoing connections involves signalling relating to power control and radio resource management, for example. Some of the signalling messages relate to single connections and others relate to system on a larger scale.

As known, problems may occur in communication networks, although the networks are designed to be as reliable as possible, taking cost efficiency into account. The problems may relate to failed call setups, dropping calls and bad throughput, for example.

Some of the signalling messages between the network elements relate to the errors occurring in the network. These messages may be called call management messages. Also other call related messages may belong to this category.

In an embodiment, the network comprises a network element 126 configured to monitor the signalling messages sent in the system. The network element 126 may analyze and monitor the messages by utilising counters to count the number of messages of a given type. For example, when a radio resource connection (RCC) is rejected in the network, the RNC responsible for the connection may send an RRC Connection Rejected message to the user equipment in regard of the connection. The network element 126 may increment a counter reserved for counting RRC rejection errors.

In an embodiment, the network element 126 is configured to analyze and monitor call management messages on a user equipment basis. Thus, the network element is configured to utilise counters to monitor signalling messages which relate to the user equipment or the connections of the user equipment.

In an embodiment, the network element 126 may be integrated in one or more radio network controllers. It may be a separate unit or it may be realised with multiple units. The realization of the network element 126 may depend on the structure and organization of the communication network.

In addition, the communication system may comprise network elements 128, 130. These network elements may be connected to the radio network controllers 108, 1 10 and to the network element 126. The network element 126 may configure the network elements 128, 130 to collect and store network signalling and traffic.

Figures 2A, 2B and 2C are flowcharts illustrating some embodiments of the invention.

In Figure 2A, the operation starts in step 200.

In step 201 , call management errors occurring on a connection between user equipment and a communication network are monitored. In an embodiment, the monitoring starts when the connection is set up. In an embodiment, the monitoring starts when the user equipment registers to a network. The registering may occur when the user equipment is powered up or when the equipment performs a handover to the network from another network. Thus, the monitoring may be performed both when the user equipment is idle and has a signaling connection to the network and when the user equipment has a speech or data connection or an active connection of another type with the network. Non-limiting examples of possible call management errors are failed call setups, dropping calls, or bad throughput.

In an embodiment, one or more Key Performance Indexes (KPI) relating to the connections between the user equipment of a subscriber and the communication network may be calculated in step 202. The Key Performance Indexes may relate to different aspects of call management. The indexes may be calculated on the basis of one or more counters incremented on the basis of errors occurring in the call management.

In an embodiment, the radio network controllers 108, 1 10 keep and update the counters counting errors and the network element 126 determines Key Performance Indexes on the basis of the counters.

In step 204, the number of errors occurring on connection of a subscriber is compared to a preset threshold value. In an embodiment, one or more Key Performance Indexes are compared to preset threshold values. Each index may have a different preset threshold value.

If a threshold value is not exceeded, the monitoring of call management errors continues in step 202. If a threshold value is exceeded, the process continues in step 206

In step 206, monitoring, storing and analyzing of subscriber specific signaling is initiated. In an embodiment, a subscriber trace is initiated on the connections of a subscriber if the number of errors on the connections is greater than the preset threshold. In an embodiment, the capturing of subscriber specific messages from a radio network controller and/or a media gateway of the communication network on the connection is initiated.

In an embodiment, the network element 126 configures the monitoring and storing to be partly executed by the network elements 128, 130, especially relating to Layer 3 messages or traces.

Figure 2B illustrates another embodiment. The operation starts in step 200. The steps 202 to 206 are similar to the steps of Figure 2A.

In step 208, a message is transmitted to a subscriber. The message may notify the user that problems in the connections of the subscriber have been detected and that steps have been taken to investigate the reasons for the errors. The message may be transmitted by using a short message service (SMS) or as an email, for example.

In step 210, it is checked whether a predefined time has elapsed since starting the monitoring and storing. If not, the process continues in step 210. If a predefined time has elapsed, the process continues in step 212.

In step 212, the monitoring and storing is terminated.

Figure 2C illustrates another embodiment. The operation starts in step 214. In step 216, subscriber specific signaling of connections between user equipment and a communication network are stored. In an embodiment, the data is stored in a ring buffer memory in such a manner that the connection data of a predetermined number of days is stored in the buffer memory. Connection data older than given number of days is overwritten.

In step 218, one or more Key Performance Indexes (KPI) relating to the connections between the user equipment of a subscriber and the communication network are determined.

In step 220, an index of a connection is compared to a preset threshold value.

If a threshold value is not exceeded, the storing of call management errors continues in step 216. If a threshold value is exceeded, the process continues in step 222.

In step 222, analyzing of connection specific signaling is initiated. The data stored in a buffer memory may be utilized. In an embodiment, a subscriber trace is initiated. In an embodiment, the capturing of subscriber specific messages from a radio network controller and/or a media gateway of the communication network on the connection is initiated. It should be noted that features of different embodiments described above may also be combined to provide other embodiments.

Figure 3 shows a signaling chart illustrating an example. Figure shows user equipment 106, a base station or Node B 100 and a radio network controller 108. In the example situation the user equipment 106 is requesting a connection (either a voice call or a data connection) from the network. One step in requesting a connection is sending a radio resource control (RCC) connection request 300 to the radio network controller 108 via the base station 100. The radio network controller 108 receives the request and begins the connection set up on the basis of the request. A successful connection set establishes a connection between the user equipment and the radio access network.

In this example, an error 302 occurs in the connection set up procedure in the radio access network. The nature of the error and the reason for the error are not relevant in this context. The radio network controller 100 detects the error 302 and sends an RRC connection reject message 304 to the user equipment to notify the equipment about the situation. In addition, the radio network controller 108 increments 306 a counter reserved for counting RRC connection related errors.

In an embodiment, the radio network controller 108 or the network element 126 is configured to calculate one or more Key Performance Indexes (KPI) relating to the connection between the user equipment and the communication network. In Figure 3, the radio network controller 108 updates 308 a Key Performance Index after incrementing a counter.

The Key Performance Indexes may illustrate different ratios related to call management. For example, the network element 126 or the radio network controller 108, 1 10 may determine indexes for call setup ratios, call drop ratios, RRC success, RAB (Radio Access Bearer) success, HSDPA (High Speed Downlink Packet Access) success ratio, HSUPA (High Speed Uplink Packet Access) success, soft and hard handoff success ratios, and average throughput over different interfaces. The above list is merely an example of possible indexes. The indexes may be determined separately for uplink and downlink directions and for different connections (speech and data, for example).

In an embodiment, the value of an index may be determined by dividing the value of a counter indicating unsuccessful attempts with the value of a counter indicating total attempts. The values of several counters may be utilized when determining the value of an index.

Figure 4 illustrates a simplified example of an apparatus of an embodiment of the invention. In some embodiments, the apparatus may be a radio network controller or a separate network element.

It should be understood that the apparatus is depicted herein as an example illustrating some embodiments. It is apparent to a person skilled in the art that the apparatus may also comprise other functions and/or structures. Although the apparatus has been depicted as one entity, different modules and memory may be implemented in one or more physical or logical entities.

The apparatus may be any server, node, host or corresponding component providing required functionality. The apparatus may also be implemented as an electronic digital computer, which may comprise a working memory (RAM), a central processing unit (CPU), and a system clock. The CPU may comprise a set of registers, an arithmetic logic unit, and a control unit. The control unit is controlled by a sequence of program instructions transferred to the CPU from the RAM. The control unit may contain a number of microinstructions for basic operations. The electronic digital computer may also have an operating system, which may provide system services to a computer program written with the program instructions.

The apparatus of the example includes a controller 400 configured to monitor call management errors occurring on connections between user equipment of a subscriber and a communication network; to compare the number of errors occurred on the connections to a preset threshold value; and to initiate monitoring and storing of subscriber specific signaling if the number of errors is greater than the preset threshold.

The controller may be configured to utilize a set of counters to count the number of different errors occurring on the connections, determine one or more performance indexes on the basis of the counters, and to compare the values of the indexes to one or more preset thresholds.

The apparatus may comprise an interface 402 for connecting the apparatus to a communication network. The interface may be realized as a wired or a wireless connection. The interface enables the apparatus to initiate a transmission of a message to a user of the connection, the message notifying the user that errors in the connection have been detected. The apparatus may further comprise a memory 404 for storing software and/or data. The memory may be integrated in the controller. The memory may store the values of counters and indexes updated by the controller and the values of the preset thresholds.

The apparatus may also include other parts and/or functionalities than those shown in Figure 4, such as a connectivity program and user interface.

The apparatus may be realized as one or more separate network elements. The controller 400 may also include circuitry, such as processors and software for implementing other functionalities of the apparatus. The controller 400 may be realised with one or more separate controlling devices.

The apparatus of Figure 4 may be implemented using at least one chipset or integrated circuit, such as ASICs (application-specific integrated circuit).

Embodiments of the invention may be implemented as computer software executable by a processor, or as a combination of software and hardware.

An embodiment provides a computer program embodied on a distribution medium, comprising program instructions which, when loaded into an electronic apparatus, perform the actions of the controller, interface and other units of the apparatuses described earlier.

The computer program may be in source code form, object code form, or in some intermediate form, and it may be stored in some sort of carrier, which may be any entity or device capable of carrying the program. Such carriers include a record medium, computer memory, read-only memory, and software distribution package, for example. Depending on the processing power needed, the computer program may be executed in a single electronic digital computer or it may be distributed amongst a number of computers.

The steps, signaling messages and related functions described above in Figures 2A, 2B and 3 are in no absolute chronological order, and some of the steps may be performed simultaneously or in an order differing from the given one. Other functions can also be executed between the steps or within the steps and other signaling messages sent between the illustrated messages. Some of the steps or part of the steps can also be left out or replaced by a corresponding step or part of the step. It will be obvious to a person skilled in the art that, as technology advances, the inventive concept can be implemented in various ways. The invention and its embodiments are not limited to the examples described above but may vary within the scope of the claims.

Claims

1 . An apparatus comprising a controller configured to

monitor call management errors occurring on connections between user equipment and a communication network;

determine a subscriber specific performance index for each connection of a subscriber;

compare the performance index of a subscriber to a preset threshold value; and

initiate monitoring of subscriber specific signaling of subscriber's connections if the performance index is greater than the preset threshold.

2. The apparatus of claim 1 , comprising a controller configured to utilize a set of counters to count the number of different errors occurred on connections of a subscriber;

determine one or more performance indexes on the basis of the counters;

compare the values of the indexes to one or more preset thresholds; and

initiate monitoring of subscriber specific signaling if the value of an index is greater than the preset threshold.

3. The apparatus of any preceding claim, wherein the controller is configured to

store subscriber specific signaling of connections between user equipment and a communication network for a predetermined time; and

monitor the stored data on the basis of the subscriber specific performance index.

4. The apparatus of any preceding claim 1 to 3, wherein the controller is configured to

initiate storing of connection specific signaling if the value of an index is greater than the preset threshold.

5. The apparatus of claim 4, wherein the controller is configured to control the storing to continue for a predefined time.

6. The apparatus of any preceding claim, wherein the controller is configured to initiate the transmission of a message to a subscriber, the message notifying the subscriber that errors have been detected in the connections of the subscriber.

7. The apparatus of any preceding claim, wherein the controller is configured to initiate subscriber trace on the connection if the number of errors on connections of a subscriber is greater than the preset threshold.

8. The apparatus of any preceding claim, wherein the controller is configured to initiate subscriber specific Layer 3 monitoring on the connection if the number of errors on the connections of a subscriber is greater than the preset threshold.

9. The apparatus of any preceding claim, wherein the controller is configured to initiate the capturing of subscriber specific messages from a radio network controller and/or a media gateway of the communication network on the connections of a subscriber if the number of errors on the connection is greater than the preset threshold.

10. The apparatus of any preceding claim, wherein a call management error comprises one of the following:

failed call setup, a dropping call, or bad throughput.

1 1 . A method, comprising:

monitoring call management errors occurring on connections between user equipment and a communication network;

determining a subscriber specific performance index for each connection of a subscriber;

comparing the performance index of a subscriber to a preset threshold value; and

initiating monitoring of subscriber specific signaling of subscriber's connections if the performance index is greater than the preset threshold.

12. The method of claim 1 1 , further comprising: utilizing a set of counters to count the number of different errors occurred on a connections of a subscriber;

determining one or more performance indexes on the basis of the counters;

comparing the values of the indexes to one or more preset thresholds; and

initiating monitoring and storing of subscriber specific signaling if the value of an index is greater than the preset threshold.

13. The method of any preceding claim 1 1 or 12, further comprising: storing subscriber specific signaling of connections between user equipment and a communication network for a predetermined time;

monitoring the stored data on the basis of the connection specific performance index.

14. The method of claim 1 1 or 12, further comprising:

initiating storing of subscriber specific signaling if the value of an index is greater than the preset threshold.

15. The method of claim 14, further comprising: continuing the monitoring and storing of subscriber specific signaling for a predefined time.

16. The method of any preceding claim 1 1 to 15, further comprising: initiating the transmission of a message to a user of the connection, the message notifying the user that errors have been detected in the connection.

17. The method of any preceding claim 1 1 to 16, further comprising: initiating subscriber trace on the connection if the number of errors on the connection is greater than the preset threshold.

18. The method of any preceding claim 1 1 to 17, further comprising: initiating capturing of subscriber specific messages from a radio network controller and/or a media gateway of the communication network on the connection if the number of errors on the connection is greater than the preset threshold.

19. The method of any preceding claim 1 1 to 18, wherein a call management error comprises one of the following:

failed call setup, a dropping call, or bad throughput.

20. An apparatus comprising

means for monitoring call management errors occurring on connections between user equipment and a communication network;

means for determining a subscriber specific performance index for each connection of a subscriber;

means for comparing the performance index of a subscriber to a preset threshold value; and

means for initiating monitoring of subscriber specific signaling of subscriber's connections if the performance index is greater than the preset threshold.

21 . A chipset comprising the apparatus of any one of claims 1 to 10.

22. A computer program comprising program code means adapted to perform any of the steps of claims 1 1 to 19 when the program is run on a computer.

23. An article of manufacture comprising a computer readable medium and embodying program instructions executable by a computer operably coupled to a memory which, when executed by the computer, perform any of the steps of claims 1 1 to 19.