U.S. patent application number 10/876234 was filed with the patent office on 2004-12-30 for selection of connection settings.
This patent application is currently assigned to Nokia Corporation. Invention is credited to Haverinen, Henry, Huotari, Anne, Jaakkola, Mikko.
Application Number | 20040264427 10/876234 |
Document ID | / |
Family ID | 8566318 |
Filed Date | 2004-12-30 |
United States Patent
Application |
20040264427 |
Kind Code |
A1 |
Jaakkola, Mikko ; et
al. |
December 30, 2004 |
Selection of connection settings
Abstract
The invention relates to selecting connection settings in a
telecommunication system. In accordance with the method, history
data is maintained, in which at least one network address is
defined and also one connection setting, which has been used for
establishing a connection to the network address. In response to
the fact that there is a need to arrange a connection to the
desired network address, the history data is checked and the
selection of the connection settings to be used is arranged by
means of the history data.
Inventors: |
Jaakkola, Mikko; (Lempaala,
FI) ; Haverinen, Henry; (Jyvaskyla, FI) ;
Huotari, Anne; (Tampere, FI) |
Correspondence
Address: |
Crawford Maunu PLLC
Suite 390
1270 Northland Drive
St. Paul
MN
55120
US
|
Assignee: |
Nokia Corporation
|
Family ID: |
8566318 |
Appl. No.: |
10/876234 |
Filed: |
June 24, 2004 |
Current U.S.
Class: |
370/338 |
Current CPC
Class: |
H04W 8/18 20130101; H04L
41/0883 20130101; H04L 29/12783 20130101; H04L 61/35 20130101; H04L
41/0859 20130101; H04W 76/10 20180201; H04W 76/19 20180201; H04L
29/12009 20130101 |
Class at
Publication: |
370/338 |
International
Class: |
H04J 001/10; H04J
003/08 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 27, 2003 |
FI |
20030967 |
Claims
1. A method for selecting connection settings in a wireless
telecommunication system, the method comprising: maintaining
history data, in which at least one network address is defined and
also at least one connection setting, which has been used for
establishing a connection to the network address, checking the
history data in response to the fact that there is a need to
arrange a connection to the desired network address, arranging
selection of the connection settings to be used by means of the
history data, and establishing a connection to a desired network
address using the selected connection settings in a terminal.
2. A method as claimed in claim 1, wherein it is checked from the
history data, whether a connection has previously been established
through the available connection settings to the desired network
address, and at least one connection setting is selected, through
which a connection has at least once been established to the
desired network address.
3. A method as claimed in claim 1, storing URL identifiers of the
network addresses or at least part of the URL identifiers of the
network addresses into the history data.
4. A method as claimed in claim 1, wherein IP addresses of the
network addresses or at least part of the IP addresses of the
network addresses are stored into the history data.
5. A method as claimed in claim 1, wherein at least one access
point, which has been used for establishing a connection to the
network address, is defined in the connection settings of the
history data, whereby the history data is checked in response to
the fact that there is a need to arrange a connection to the
desired network address through an access point, and the selection
of the access point is arranged by means of the history data.
6. A method as claimed in claim 5, wherein information about
whether a connection has previously been established to the desired
network address through a proposed access point is used as a
criterion in an access point selection algorithm.
7. A method as claimed in claim 5, wherein an identifier of an
access point offering wireless connections for the terminals of at
least one wireless local area network is defined in the connection
settings of the history data, whereby the available access points
and the history data associated therewith are defined in the
terminal on the basis of the identifiers included in the messages
received over the radio interface from the access points.
8. A method as claimed in claim 5, wherein an identifier of an edge
node of at least one IP network and/or parameters required for
establishing a connection to at least one edge node in the IP
network is defined in the connection settings of the history
data.
9. A wireless telecommunication system comprising at least one
terminal and a network, wherein the wireless telecommunication
system is configured to: maintain history data, in which at least
one network address is defined and also one connection setting,
which has been used for establishing a connection to the network
address, check the history data in response to the fact that there
is a need to arrange a connection to the desired network address,
select the connection settings to be used by means of the history
data, and the connection establishment is arranged to a desired
network address using the selected connection settings in the
terminal.
10. A wireless terminal, wherein the wireless terminal is
configured to maintain history data, in which at least one network
address is defined and also at least one connection setting, which
has been used for establishing a connection to the network address,
the wireless terminal is configured to check the history data in
response to the fact that there is a need to arrange a connection
to the desired network address, the wireless terminal is configured
to select the connection settings to be used by means of the
history data, and the wireless terminal is configured to establish
a connection to the desired network address using the selected
connection settings in the terminal.
11. A wireless terminal as claimed in claim 10, wherein the
wireless terminal is configured to define at least one access
point, which has been used for establishing a connection to the
network address, in the connection settings of the history data,
whereby the wireless terminal is configured to check the history
data in response to the fact that there is a need to arrange a
connection to the desired network address through a new access
point, and the wireless terminal is configured to select the access
point by means of the history data.
12. A wireless terminal as claimed in claim 11, wherein the access
point is an access point offering wireless connections to the
terminal of a wireless local area network and the wireless terminal
comprises means for establishing a connection to the access points
of the wireless local area network, whereby the wireless terminal
is configured to define the available access points and the history
data associated therewith concerning the access points on the basis
of the identifiers included in the messages received over the radio
interface.
13. A computer software product for controlling the wireless
terminal in response to executing the program code included in the
computer software product in a processor of the terminal, wherein
the computer software product comprises: a program code portion for
controlling the terminal to maintain the history data, in which at
least one network address is defined and also at least one
connection setting, which has been used for establishing a
connection to the network address, a program code portion for
controlling the terminal to check the history data in response to
the fact that there is a need to arrange a connection to the
desired network address, and a program code portion for controlling
the terminal to select the connection settings to be used by means
of the history data.
Description
FIELD OF THE INVENTION
[0001] The invention relates to selecting connection settings and
more particularly to selecting connection settings in a
telecommunication system comprising a wireless access network.
BACKGROUND OF THE INVENTION
[0002] In addition to data services offered by Public Land Mobile
Networks (PLMN), various wireless local area network techniques
offering a broadband wireless data transmission service within a
limited coverage area are developed for moving users. Examples of
such techniques are the IEEE 802.11-based WLAN networks. Wireless
local area networks can be used to offer data transmission services
in hot spots, such as offices or airports. The wireless local area
networks are frequently connected to external networks, for
instance in order to enable access to the Internet. The data
transmission rates offered by wireless local area networks are
generally considerably higher than the data transmission rates
offered in the PLMN networks. Thus, in places, where a local area
network can be used, the aim is to establish a connection to the
desired network address through the wireless local area network.
The establishment of a connection to wireless local area networks
and through them to other networks and the transfer from one
network to another is, however, not always possible and has been
more difficult for the user than in the PLMN networks, which are
provided with a well operating roaming functionality.
[0003] Patent application publication WO 01/63843 discloses a
method particularly for establishing a connection to a wireless
local area network. The settings required for being connected to
networks and different network resources are stored into
information sets in the wireless terminal. The information sets are
preferably defined separately for each network and they can be
referred to as profiles. What can be stored into the information
sets is WLAN-specific data, such as a network name, a channel
setting, an operating mode setting and data security settings, as
well as other settings, especially settings associated with the use
of a TCP/IP protocol. When an access point to be used has been
selected, a connection is established to the access point in
accordance with the settings described in the information set
included in the network name. This solution provides such an
advantage that the users do not have to know which settings are
required and how the settings have to be changed when establishing
a connection to the network; instead the pre-stored settings can be
used to establish a connection to different networks.
[0004] When the user moves to a new location, his/her terminal may
be provided with several wireless local area networks. For example,
a WLAN terminal may, based on scanning network names, be able to
set up a list on available WLAN access points. However, several
wireless local area networks are not connected to other networks or
a connection to a desired network address cannot be established
owing to, for instance, missing roaming agreements, in which case
the connection cannot be established through the wireless local
area network to the desired network address. When the user or
terminal selects an access point on the basis of a network
selection algorithm, a connection cannot necessarily be established
through the access point to the desired network address, for
instance to a Virtual Private Network (VPN) gateway of a
company.
BRIEF DESCRIPTION OF THE INVENTION
[0005] It is an object of the invention to generally improve the
selection of connection settings in order to achieve a more
reliable connection establishment. The object of the invention is
achieved with a method, a wireless telecommunication system, a
terminal and a software product, characterized in what is disclosed
in the independent claims. Preferred embodiments of the invention
are disclosed in the dependent claims.
[0006] In accordance with the invention, history data is
maintained, in which at least one network address and at least one
connection setting are defined, wherein the connection setting has
been used for establishing a connection to the network address. The
history data is checked in response to the fact that there is a
need to arrange a connection to the desired network address. The
selection of connection settings to be used is arranged using the
history data. It has been observed in the invention that the
history data associated with the network address can generally be
maintained for any connection set defined by one or more connection
settings. An example of a connection setting is an identifier
identifying a WLAN access point. The arrangement according to the
invention provides such an advantage that as connection settings
are being selected, it is possible to pay attention to whether a
connection has been established through the possible connection
setting to the desired network address. When such connection
settings are preferred, from which connections have previously been
established to the network address, the connection establishment to
the desired network address succeeds more frequently. Drawbacks
occurring during unsuccessful connection establishment can thus be
avoided.
[0007] In accordance with an embodiment of the invention, at least
one access point, which has been used for establishing a connection
to the network address, is defined in the connection settings of
the history data. Then the history data is checked in response to
the fact that there is a need to arrange a connection through an
access point to the desired network address, and the access point
is selected using the history data. It should be noted that the
term access point is to be understood in a broad sense and that it
may refer to a physical access device or to a logical access point.
This embodiment can be applied in any roaming situation, also in
situations, in which the connection responsibility of an
established connection should be transferred to be carried out
through another access point (handover). Since this embodiment
enables to avoid or at least to reduce the choice of incorrect
access points, the handover of the connection to a new access point
can be carried out faster, which is particularly important for
time-critical applications, such as multi-media applications.
[0008] In accordance with another embodiment of the invention,
information about whether a connection has previously been
established through a possible access point to the desired network
address is used as a criterion in the selection algorithm of the
access point. This embodiment provides such an advantage that an
access point can be selected that is far better concerning other
properties, for instance signal level, (according to predetermined
selection conditions), through which a connection has nevertheless
not previously been established to the network address.
[0009] In accordance with still another embodiment of the
invention, the history data enables to check whether a connection
has previously been established through the available connection
settings to the desired network address. Such a check enables to
select the connection settings, by means of which a connection has
previously been established at least once to the desired network
address. This embodiment allows avoiding completely the use of such
connection settings, which have not previously been used to
establish a connection to the desired network address.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] In the following the invention will be described in greater
detail by means of some embodiments with reference to the
accompanying drawings, in which:
[0011] FIG. 1 shows a wireless telecommunication system;
[0012] FIG. 2 illustrates a method according to an embodiment of
the invention for selecting connection settings;
[0013] FIG. 3 illustrates a method according to an embodiment of
the invention for maintaining history data; and
[0014] FIG. 4 illustrates a method according to an embodiment of
the invention for selecting an access point.
DETAILED DESCRIPTION OF THE INVENTION
[0015] An embodiment of the invention is described in the following
example system comprising a wireless local area network. However,
the invention can be used for selecting one or more connection
settings of any network resource, for instance for selecting one or
more connection settings of a PLMN network. An example of a
wireless local area network technique is a system supporting the
WLAN radio interface defined in the IEEE 802.11 standards. The
invention can also be applied in other types of wireless local area
network techniques, for instance in Bluetooth, HiperLAN (High
Performance Radio Local Area Network) or BRAN (Broadband Radio
Access Network) equipment.
[0016] FIG. 1 shows a wireless telecommunication system comprising
at least one terminal TE, networks NW1, NW2 comprising a wireless
local area network, GSM/GPRS network NW3 and an Internet service
provider network NW4. The network NW1, NW2 comprising a wireless
local area network comprises wireless local area network access
points AP, which operate as base stations and which can also be
referred to as base stations, and an apparatus typically referred
to as a portal PT, through which a connection can be arranged from
a wireless local area network to other networks, such as the
Internet. The portal PT may also operate as an access controller of
the wireless local area network, in which case the portal PT
handles some of the functions of the wireless local area network.
It should be noted that any terminal equipment in the local area
network may operate as the portal PT to other networks, such as a
local area network IP router, a home network ADSL device or an
apparatus operating as a VPN gateway. The Internet service provider
network NW4 comprises an Internet access point ISP AP for
connecting the connections established through the portal PT of the
network NW2 to the Internet and a server S, for instance an e-mail
server maintained by the service provider. Other networks may also
comprise different servers S, such as an e-mail server of a company
or a WWW server connected to the Internet. The access equipment
(PT, ISP AP, GPRS AP) at the edge of the networks typically
comprise a firewall functionality to ensure information security.
The GSM/GPRS network NW3 comprises well-known network elements
defined in the GSM/GPRS specifications, such as GPRS access point
equipment GPRS AP connecting the GPRS network to other
networks.
[0017] The terminal TE comprises memory, a user interface and a
central processing unit comprising one or more processors. The
terminal TE may also comprise other memory means, such as a
removable IC card and/or a memory card as well as means for reading
the card. For example, connection settings required in connection
establishment and data required for selecting the settings can be
stored in the internal and/or external memory. Typically, several
connection settings are stored as alternative profiles or
connection setting sets, in which case one of the connection
settings must be selected when establishing a connection. The
computer program codes to be executed in the central processing
unit can be used to arrange the terminal TE to carry out the
inventive operations, some of the embodiments thereof being
illustrated below in FIGS. 2, 3 and 4. As mentioned above, the
invention can also be applied in other terminals than those
establishing WLAN connections. Such terminals can be arranged to
carry out a method illustrated in the following as well as
different embodiments thereof by executing a computer program code.
It is also possible to use hardware solutions or a combination of
hardware and software solutions to implement the inventive
features. The terminal TE may be a multifunctional terminal, thus
comprising in addition to the WLAN functionality also other data
transmission properties, for instance a transceiver for
communicating with the GSM/GPRS network or 3GPP system (3.sup.rd
Generation Partnership Project) network and in accordance with an
embodiment also means for selecting the connection settings to be
used in this kind of network. The terminal TE may for example be a
PDA device, a laptop computer connected to a device offering radio
access (e.g. WLAN card) or a combination of a PDA device and a
mobile phone.
[0018] FIG. 2 illustrates a method according to an embodiment of
the invention for selecting connection settings. In this method,
history data is maintained 201, in which network addresses are
defined, to which a logical connection has been established. Each
network address was provided with at least one connection setting,
which was used when a connection is established to the network
address. Maintaining the history data is illustrated in more detail
in FIG. 3. Network addresses can be identified using any identifier
of the network resource concerned. Typically, logical connections
are established from the terminal TE to a packet-switched IP-based
network, in which case the data concerning the network addresses
represents IP addresses or other identifiers, from which the IP
address can be defined. The invention is particularly well suited
to be used for TCP/IP connections. In accordance with an
embodiment, URL identifiers of the network addresses are defined to
the history data. It is also possible to store only a part of the
actual network address, such as the prefixes of the network
addresses in IPv6 mode or the domain name of the URL identifiers of
the network addresses.
[0019] When a need 202, 203 arises to establish a connection to a
desired network address, the data on the available connection
settings is defined 204. Data concerning the connection settings
can be obtained from an external network element, from the memory
of the terminal TE or from an external memory means, such as an IC
card. What can be defined as available connection settings are all
connection setting sets included in the terminal TE, or the
external memory means, or the connection settings can be dropped,
for instance, in the terminal TE, based on the currently used
networks and/or services. The available connection sets can be
defined also based on data received from external network elements.
The process may proceed to step 204 when a need 202 arises to
change valid connection settings to an already existing connection
(or at least to define, whether connection settings offering a
better connection are available), for example to change the access
point AP to be used, or when a need 203 arises to select connection
settings for a new connection.
[0020] When the method is applied for selecting access points AP of
a wireless local area network according to an embodiment, the
terminal TE may receive from the access points AP identifiers,
which identify the access point AP or the network, to which the
access point AP belongs. The process typically proceeds to step 202
when it is observed in the terminal TE, on the basis of radio
measurings, that the quality of the connection offered by the
currently serving access point AP is too poor based on at least one
predetermined handover criterion. In turn, the process generally
proceeds to step 203 when an input is received from the user
concerning connection establishment to the network address selected
by the user. Collecting data about WLAN access points AP can be
implemented by carrying out scanning from the available networks.
Scanning the access points AP is as such a basic functionality
defined in the IEEE 802.11 standard, in which the TE checks the
radio channels one by one by sending probe requests and by
searching for probe responses. The TE sends probe request messages
to local access points AP and waits for Probe response messages. In
general, a Probe response message comprises a network name, to
which each access point belongs.
[0021] In step 205, it is checked from the history data, whether a
connection has previously been established using any one of the
available connection settings to the network address of an existing
connection or of a connection to be established. The check 205 can
be carried out in accordance with an embodiment by searching for
entries in the history data, in which the desired network address
is presented. As a response, the search reveals entries, which
comprise identifiers identifying a connection setting set or a set
of connection setting sets, such as WLAN network names, which are
compared to the identifiers obtained in step 204. What remain based
on such a check are the entries in the history data concerning the
available access points. Several other ways exist to store and to
retrieve the history data associating the connection settings and
the network addresses.
[0022] In step 206, the connection settings to be used are selected
taking into account whether a connection has been established to a
network address of an existing connection or of a connection to be
established using the proposed connection settings. In accordance
with an embodiment, the present method is applied when selecting an
access point, in which case the history data can be used in an
access point (handover) change algorithm or in an access point
selection algorithm when establishing a new connection.
[0023] In accordance with an embodiment, the selection of such
connection settings, by means of which a connection to the desired
network address has not previously been established, is prevented.
In accordance with another embodiment, such connection settings,
through which a connection to the desired network address has not
previously been established, can be selected only if such
connection settings, through which a connection to the desired
network address has previously been established, are not available.
Such a situation may arise for instance if the history data does
not show any entries to the desired network address or if the
connection settings associated with the network address are not
available based on the check of the available network resources
performed in the terminal (for example the scanning of the access
points AP in the wireless local area network). After this, using
the selected connection settings, a connection can be established
in step 207.
[0024] In accordance with an embodiment, for selecting the
connection settings, the user is after step 205 provided with data
on the available connection settings using the history data. The
history data may show the user at least whether an attempt has been
made to establish a connection to the desired network address
through the at least one connection setting in question. The user
may thus select 206 the connection settings to be used based on the
connection settings shown. It is also possible that the user is
requested to confirm the use of the connection settings selected by
the connection setting selection algorithm included in the
terminal. In accordance with still another embodiment, the user is
presented with only the available connection settings, through
which a connection has previously been established to the desired
network address. These embodiments can be applied in embodiments
applying any connection settings, for instance in the embodiments
illustrated in FIGS. 2, 3 and 4. It is an advantage that the user
has the power to decide when connection settings are being selected
and the history data can also be used when the user selects
connection settings or when the proposed connection settings are
being confirmed.
[0025] FIG. 3 illustrates maintaining history data in accordance
with an embodiment. When a need arises to establish a connection to
a particular network address, the connection settings to be used
are selected in the terminal TE for instance as illustrated above
and a connection establishment request is sent 301 in accordance
with the connection settings. The terminal TE detects in step 302
whether the connection establishment to the desired network address
has been successful.
[0026] In accordance with an embodiment, the method is applied in a
wireless local area network, whereby well-known connection
establishment functions of the wireless local area network can be
used when establishing a logical connection between the terminal TE
and the access point AP. The connection establishment request can
then be sent in step 301 to the access point AP of the wireless
local area network according to the network name defined in the
connection settings. The failure of a connection can be detected
302 for example in response to a message determining the failure of
a connection to be established to the access point AP or the
failure of a connection to be established to the desired network
address or in response to the fact that no response message is
received to message 301. If the connection establishment fails, it
is checked 303, whether the desired network address is already
defined in the history data. If the network address is defined in
the history data, the entry associated therewith can be removed
304. If the network address has not been defined in the history
data, no changes need to be made in the history data 308. In
accordance with an embodiment, it is checked if the history data
includes an entry associating the selected at least one connection
setting (used in step 301) with the network address, i.e. whether a
connection has previously been established successfully to the
desired network address by means of the connection setting. If this
is the case, such an entry is removed 304, while the entries
associated with other connection settings remain in the history
data. When connection establishment has failed, it is possible to
try to establish the connection once again using one or more
alternative connection settings, meaning that the process may
proceed to step 202 in FIG. 2. The history data can be stored for
instance in a search table, from which the entries included in the
network address to be searched can easily be found when changing
the connection settings after connection establishment when
selecting the connection settings.
[0027] A successful connection can be detected from a response or
acknowledgement message received from the desired network address.
In step 305, it is checked whether the desired network address is
defined in the history data. The check can be carried out in the
same way as in step 303. If the history data does not include an
entry associating at least one selected connection setting with the
network address, then a new entry is added 306 to the history data.
If the previous entry is found in the history data, it can be
updated 307 along with a new connection.
[0028] In accordance with an embodiment, a count is maintained in
the history data concerning the successful connection
establishments, the count being incremented in step 307. In
accordance with another embodiment, time information is maintained
on the successful connection establishments in the history data, in
which case a time stamp can be added into the history data
concerning the new connection establishment or the previous time
stamp can be replaced using the time stamp of a new connection.
According to still another embodiment, the history data is stored
in a buffer memory, whereby the oldest entry (preferably the one
associating the access point with the network address) can be
removed along with the new entry. The amount of memory the history
data requires can therefore be limited. Various buffer memory
techniques that can be utilized for storing history data are known
in the field of information technology. In practice, connections
are established from the terminal TE to a fairly limited number of
network addresses, in which case the terminal TE does not have to
maintain a large amount of history data in order arrange a
well-functioning selection of connection settings.
[0029] The use of history data associating connection settings with
network addresses has above been illustrated in general. Reference
has previously also been made to an embodiment, in which at least
one access point is defined in the connection settings of the
history data that has been used when establishing a connection to
the network address. In the history data, a network address can be
associated with any one of one or more connection setting sets, by
which a connection has been established to the network address. The
connection settings may represent any protocol layer parameters,
such as the parameters of a physical layer, a transfer connection
layer, a network layer, a transport layer, and/or also the
parameters of higher layers. The connection settings may define the
network technique to be used, such as the wireless local area
network (for example WLAN or Bluetooth), GPRS data, GSM data. The
connection settings may define different technology-specific
parameters, such as a technology-specific identifier identifying an
access point and/or a network and parameters to be used for
identifying a user, such as a user identifier, information about
the identification method in use (for example password
identification, SIM identification (Subscriber Identity Module) or
certification identification), as well as the parameters required
by the identification method. For example, when a connection has
been established to a certain gateway (the address of which may be
the desired network address), the history data may be provided with
an identification method, such as SIM identification. Later, when a
connection is to be established to the same gateway, the SIM
identification can automatically be selected to be used as the
identification method. This embodiment provides such an advantage
that the correct identification settings of the user and possibly
the user identifications can easily be selected when establishing
the connection. Different embodiments are described in the
following in more detail, in which the history data is utilized for
the selection of the access point and/or the access point
settings.
[0030] FIG. 4 illustrates an embodiment, in which changing the
access point of an active connection is defined on the basis of the
history data. A connection is established 401 from the terminal TE
to the network address through the access point, which is for
instance selected using the method applying the history data
illustrated above. In this embodiment, the history data binds
access point identifiers with network addresses, to which the
connection is established through the access points defined by the
identifiers. When a need is detected 402 to change the available
access point, the data concerning the available access points for
the terminal TE is checked 403. The available access points are
compared and checked 404 to note whether a better access point than
the currently serving access point is available. Then the
properties of the available access points can be compared with the
properties of the currently serving access point. A better access
point is available, if the properties of an access point are better
in accordance with the change criteria of one or more predetermined
access points than the properties of the currently serving access
point.
[0031] When changing an access point AP of a wireless local area
network according to an embodiment, the access points AP can be
compared on the basis of received access point reports and signal
levels measured in the terminal TE of the signals received from
different access points AP. At least the signal level is taken into
account, when the available access points AP are compared.
Information about the access point reports, such as the load of the
access point, supported data rates and security information can
also be taken into account when comparing the access points AP.
[0032] If at least one better access point is available for a
terminal, it is checked 405 based on the history data, if a
connection to the network address of an active connection has
previously been established (at least once) there through. If this
is the case, the access point is changed 406. Thus, a connection is
established for the terminal to the network address through the
selected new access point and the connection through the original
access point is released. Connection establishment to a selected
access point can be arranged using the setting data specific to the
access point and/or network stored in the terminal TE. In
accordance with an embodiment, a connection can be established to
the access point AP of the wireless local area network by utilizing
for example the information sets presented in patent publication WO
01/63843.
[0033] If, on the basis of the check 405, a connection has not been
established from the proposed best access point to the network
address, then the access point is not changed 407 in accordance
with the method, meaning that the connection is maintained in the
currently serving access point. If several access points are
available on the basis of the check 404, the process may proceed in
accordance with an embodiment from step 405 again to step 405
instead of step 407, thus checking the history data of the next
best access point.
[0034] By means of the above-illustrated embodiment, it is possible
to prevent the change of access points, if the proposed access
point has not previously been used successfully to establish a
connection to the network address of the connection to be
transferred.
[0035] The invention can be applied in addition to the example
illustrated in FIG. 4 also for changing several connections
established from the terminal TE from one access point (several
access points) to another. It should also be noted that the
invention can be applied when selecting access points of different
network techniques, for example when deciding whether to transfer
from a 3GPP network to a wireless local area network or vice versa.
Thus, history data can be maintained in the terminal TE for
different connection and/or network types, and access points
supporting other techniques too can be compared based on the
history data. Thus, also the choice of network and/or connection
type may be defined based on the history data.
[0036] In accordance with an embodiment deviating from FIG. 4, the
connection establishment data associating the access point with the
network address defined in the history data is used as a criterion
in the selection algorithm of the access point, when selecting an
access point for a new connection or when changing the access point
of an active connection. Then access points, through which a
connection has previously been established to the desired network
address, can be preferred. Then again, if an access point provided
with distinctly better properties (in accordance with predetermined
conditions), through which access point a connection has not
previously been established to the network address, said access
point can be selected by means of such an algorithm.
[0037] A method for selecting an access point of a wireless local
area network is presented in patent application publication WO
01/63842. In accordance with the teaching of the method, the
terminal TE selects in the first step the first access point, which
is provided with the best connection attributes among the available
access points with the same network name as the currently serving
access point. The TE also selects in the first step a second access
point, which is provided with the best connection attributes among
the available access points with a different network name than the
currently serving access point. After this, in the second step, the
connection attributes of the first access point and the second
access point are compared. The connection is changed to the second
access point only if the differences between the connection
attributes to be compared meet the predetermined conditions.
Consequently, this facilitates maintaining the connection as long
as possible in the access points provided with the same network
name, thus avoiding the change of the network settings. At this
stage, in accordance with an embodiment of the present invention,
what is also used as a connection criterion, when comparing the
access points (in the first step and/or in the second step), in
addition to other criteria such as the signal level, is the fact
whether a connection has previously been established successfully
through the access point to the network address of the connection
in question. This criterion can alternatively be used as a
pre-elimination criterion before comparing the access points.
[0038] The access point may be instead of an access point in a
wireless local area network, for instance an Internet service
provider access server ISP AP, an apparatus offering a
circuit-switched data connection (such as a mobile switching
centre) or a GPRS access point GPRS AP. Then the history data may
comprise, depending on the available technology, for example a GPRS
APN (Access Point Name) or a telephone number as the identifier of
the access point. In accordance with an embodiment of the
invention, the access point to be selected is an edge node in an IP
network, for example the Internet. As described above, the terminal
TE then maintains history data on the access points and the network
addresses reached through said access points, for example a list of
recommended IP edge nodes. This embodiment provides such an
advantage that the Internet access point can be selected more
reliably than before. In accordance with an embodiment, the
invention is applied in a system, which supports a Mobile IP
protocol. The mobile IP protocol allows the terminal TE to move
from a sub-network to another and to communicate using the same IP
address. With an embodiment of the invention, the access point that
enables the change of connection in the system supporting mobile IP
can also be selected more reliably than before.
[0039] Table 1 illustrates by way of example the history data
maintained in the terminal TE.
1 TABLE 1 Network Network service Access point address WLAN Corp
WLAN NW1 mail.corp.com WLAN Corp WLAN NW1 mail.corp.com WLAN
Hotspot1 www.nokia.com WLAN Hotspot1 www.nokia.com WLAN StevenNet
NW2 HomeServer GPRS Corporate GPRS AP mail.corp.com GPRS Corporate
GPRS AP www.nokia.com GPRS Public GPRS AP www.nokia.com
[0040] With reference to FIG. 1 and Table 1, an example person
Steven may use the terminal TE, in which the history data according
to table 1 is stored on the basis of previous connections. Steven
uses the e-mail server S (mail.corp.com) of his company in the
company network NW1 through a WLAN access point AP of the network
NW1 (the network name of which may be Corp. WLAN NW1, for example).
When the terminal TE is loaded with a large e-mail file, Steven
moves away from the office and the connection offered by the
wireless local area network NW1 fades substantially. However, the
TE automatically transfers the connection to the GSM/GPRS network
NW3 and especially to be carried out through the GPRS access point
GPRS AP, since in accordance with the history data a connection has
previously been established through the GPRS access point GPRS AP
to the network address of the e-mail server S mail.corp.com. In
another example, Steven wishes to visit the WWW page www.nokia.com
while traveling in a train and to establish a connection based on
the history data and the available GSM/GPRS network to said address
through the GPRS access point GPRS AP (Public GPRS AP) of the
operator. When the train stops at a station, a local local area
network (Hot Spot1) is available, into which the TE transfers, on
the basis of the history data and other criteria (for instance a
higher data rate). When Steven returns home, the terminal TE
changes the connection to said address to be implemented by the
access point AP of the home network NW2.
[0041] As shown above, in addition to the network and access point
data, the history data may include count information about the
number of successful connections or other information, for example,
for a selection algorithm or for establishing a connection. It is
possible that several alternative connection setting sets are
defined in the terminal that may be used to establish a connection
to one physical access point, for instance to the access point
device AP of the wireless local area network. Then, the terminal
may maintain these connection setting sets as logically alternative
access points and they can be separated in the history data. This
embodiment allows selecting or favoring connection setting sets, by
which the connection establishment has previously been successful.
This embodiment may for instance complement the selection of the
above-described wireless access point device on the basis of the
network names. In other words, when the physical access point has
been selected, it is possible to select even more detailed
connection parameters, by means of which the connection is
established. The parameters defined in the history data of the
access point may include for instance parameters associated with
identifying the user or tunneling data. The tunneling data may for
instance define, whether Virtual Private Network (VPN) tunneling or
some other type of tunneling of a network layer or a higher layer
is used. If tunneling is used, the access point data may also
include the parameters required by the tunneling, such as the
address of the VPN gateway.
[0042] As an example, logical Internet access points (IAP), in
which several of the above-illustrated parameters associated with
the connection establishment are defined, can be stored in the
Symbian operating system. When the present method is applied to
these separate logical Internet access points, meaning that the
Internet access points are bound to the desired network addresses,
the selection of the logical Internet access point, or connection
setting set, can be alleviated and the Internet access point can
for instance be automatically selected, according to which a
connection has previously been established to the desired network
address. Thus, when establishing the application layer connection,
when the target network address of the application level is known,
the internet access point to be used first can be selected.
[0043] In accordance with a further embodiment of the invention,
the terminal TE maintains data on the connection settings, by which
no connection has been successfully established to the desired
network address. This data can complement the data to be maintained
on the basis of the above-described successful connections or
replace them completely. Consequently, the functions described
above can be utilized when selecting the connection settings, for
example the WLAN access point or Internet access point, but in such
a manner that the connection settings that have not previously been
able to successfully establish a connection to the network address,
are not selected to be used for connection establishment or they
are avoided for instance in the selection algorithm of the access
point (for example, using different criteria for them or by
emphasizing them differently than other connection settings).
[0044] It is apparent for those skilled in the art that as
technology advances the basic idea of the invention can be
implemented in various ways for selecting different access points.
The invention and the embodiments thereof are therefore not
restricted to the examples described above but may vary within the
scope of the claims.
* * * * *
References