NETWORK NODE CONTROL
FIELD OFTHE INVENTION
The present invention relates to methods of controlling a network node, network nodes
and a computer program product.
BACKGROUND
In many mobile telecommunications systems such as, for example, a third generation
(3G) evolved universal terrestrial radio access network (E-UTRAN) telecommunications
system, number of base stations (E-UTRAN NodeBs - eNBs) are arranged to
communicate with a number of user equipment (UEs). A number of channels are
provided between the base stations and the user equipment to support this
communication. Each base station is geographically separated from the others in
order to provide communications coverage over a wide area. Also, each base station
is typically arranged to support a number of "sectors" extending outwards from the
base station location.
User equipment may establish a communications link with a base station when within its
associated sector. As user equipment roams throughout the network, it will eventually
leave its current sector and enter a new sector. When this happens, the current base
station will need to "handover" the user equipment to a base station associated with
that new sector. To assist in this process, the user equipment typically continually
attempts to identify further base stations with which it may establish a communications
link. Ukewise, the network itself may derive information from the user equipment and
indicate to the user equipment details of the most likely base station to which a
handover may occur. The sectors generally overlap somewhat geographically to
enable communication with an existing base station to be retained until
communication with a new base station can be established and a handover can
occur. It can be seen that this enables user equipment to roam throughout the
network, with the user equipment being handed over from base station to base station.
It will be appreciated that this arrangement helps to ensure that user equipment can
reliably establish a connection and enables the user equipment to roam through the
network. However, a problem with the arrangement described above it that changes
to each network node are difficult to administer.
Accordingly, it is desired to provide a n improved technique for administering such
changes.
SUMMARY
According to a first aspect, there is provided a method of controlling a network node,
comprising the steps of: identifying, to said network node and other network nodes
within a predefined network node controlling cluster for said network node, at least one
proposed change to said network node; and in the absence of a n indication from said
other network nodes within said network node controlling cluster rejecting said at least
one proposed change to said characteristics of said network node, subsequently
making said at least one proposed change to said characteristics of said network
node.
The first aspect recognises that controlling the characteristics of every network node
within the network can be difficult to achieve. If the changes are controlled centrally
then a great deal of information and signalling messages may be required to be
provided to a centralised controller in order to enable that centralised controller to
make configuration decisions and communicate these to each of the network nodes.
Likewise, enabling every network node to make its own configuration changes based
on the information it has available may lead to sub-optimal changes being made since
insufficient information may be available to individual network nodes which may then
make a configuration changes which is advantageous to that network node but which
causes overall detriment to the network asa whole or to other network nodes. Also,
whilst in some network arrangements (such as in a Universal Mobile
Telecommunications System - UMTS), each network node, such as a base station, is
under the control of a radio network controller (RNC) that has a view of the traffic
beyond the particular base station, in other arrangements (such as in Long Term
Evolution - LTE), there is no such RNC concept and the Radio Access Network (RAN) is
flat consisting of distributed base stations. It is therefore particularly difficult in that type
of architecture to find a n appropriate technique for control.
Accordingly, proposed change to the characteristics of a network node can be
identified. These changes may be predetermined between the network node and the
controlling cluster or may be identified by the network node to the controlling cluster.
Should no node in that cluster provide a n indication rejecting the proposed change,
then the network node is then able to make those changes to its characteristics should
it decide to d o so. That is to say, that although a proposed change has been identified
a s being allowed to occur, there is no obligation on the network to implement that
change immediately. However, should any network nodes within the cluster determine
that the proposed change to the characteristics of the network node would cause a
detrimental effect to that other network node or should those other network nodes be
able to determine that the proposed changes would be to the overall determinant of
the network, then a n indication is provided to prevent the network node from making
the proposed changes. In other words, the network nodes within the controlling cluster
can be considered to be "masters' which control the operation of 'slave' network
node, and no changes can be made by the slave network node without the
agreement of all the master network nodes within the controlling cluster. This approach
helps prevent network nodes from acting autonomously in a way that would be
detrimental to other network nodes in the network. This approach is particularly
efficient in an LTE architecture or other architectures having a generally flat network of
base stations.
In one embodiment, said step of identifying comprises: upon determining a proposed
change to characteristics of said network node, providing a first indication of said
proposed change to said other network nodes within said predefined network node
controlling cluster for said network node and said step of making comprises: in the
absence of said indication from said other network nodes within said network node
controlling cluster rejecting said proposed change to said characteristics of said
network node, subsequently making said proposed change to said characteristics of
said network node. Accordingly, when a network node determines that a proposed
change to the characteristics of that node is to occur, it provides a n indication of the
change to other network nodes which belong to a predefined cluster which controls
the network node. Should no node in the cluster provide a n indication rejecting the
proposed change, then the network node makes those changes to its characteristics.
However, should any network nodes within the cluster determine that the proposed
change to the characteristics of the network node would cause a detrimental effect to
that other network node or should that other network node be able to determine that
the proposed changes would be to the overall determinant of the network, then a n
indication is provided to prevent the network node from making the proposed
changes. This approach helps prevent network nodes from acting autonomously in a
way that would be detrimental to other network nodes in the network. This approach is
particularly efficient in a n LTE architecture or other architectures having a generally flat
network of base stations.
In one embodiment, the step of providing comprises: providing the first indication by
transmitting a message indicating the proposed changes to the other network nodes.
In one embodiment, said step of identifying comprises: identifying, to said network
node and said other network nodes within said predefined network node controlling
cluster for said network node, said at least one predetermined proposed change that
may be made by said network node ; and said step of making comprises: subsequently
making said at least one predetermined proposed change only when all other network
nodes within said network node controlling cluster have each provided a second
indication agreeing to said at least one predetermined proposed change.
Accordingly, one or more predetermined proposed changes to the network node may
be pre-identified by both said network node and said controlling cluster. For example,
it may be pre-identified that a network node may switch off or perform some other
action or function whenever possible. This proposed change is known to both the
network node and the controlling cluster. As network nodes within the controlling
cluster determine that these pre-identified proposed changes can be made by the
network node, this is identified to the network node. For example, network nodes within
the controlling cluster may each determine, based on the conditions they are
experiencing, that the network node may switch off and this is indicated to the network
node either passively or actively. Once the network node determines that all of the
network nodes in the controlling cluster agree to one of these pre-identified changes,
the network node is then free to subsequently make that change, when convenient to
do so. In this way, pre-agreed optimisations to the characteristics of the network node
can be identified to the network nodes as being possible to make without the network
node having to provide a request to the controlling cluster.
In one embodiment, the method comprises the step of: upon receipt of the indication
from the one of said other network nodes within the network node cluster rejecting the
proposed change to the characteristics of the network node, abandoning the
proposed change to the characteristics of the network node. Accordingly, should the
indication rejecting the proposed change be received from any network node within
the cluster within a predetermined period, the proposed changes to the characteristics
are abandoned.
In one embodiment, the method comprises the step of: upon receipt of the second
indication from all the other network nodes within the network node controlling cluster
accepting the proposed change to the characteristics of the network node, making
the proposed change to the characteristics of the network node. Accordingly, the
proposed changes may only be made after each network node within the cluster
provides an indication that these changes are acceptable.
In one embodiment the method comprises the step of: upon receipt of a third
indication from one of said other network nodes within the network node controlling
cluster requesting reinstatement of the characteristics of the network node, reversing
changes made to the characteristics of the network node. Accordingly, even after the
proposed changes to the characteristics have been made, should a subsequent
indication be received from any network node within the cluster requesting
reinstatement of the previous characteristics of the network node, those previous
characteristics, which existed before the changes were made, are restored. It will be
appreciated that this enables a network node within the cluster which did not
anticipate that the changes that were going to be made to the network node would
cause detriment, to make the network node reverse those changes should such
detriment subsequently occur.
In one embodiment, the third indication from a network node within the network node
cluster requesting reinstatement is received in a message from that network node.
In one embodiment, the proposed change is a change in transmission power of the
transceivers. Accordingly, should an energy efficiency scheme be implemented which
changes transmission power of the transceivers in order to conserve energy, the
network node cannot change the transmission power autonomously without asking
permission from all cells in its controlling cluster. Should any of the cells within the cluster
object, then the changes in the transmission power cannot be made. Thereafter, once
the changes are made, any request coming from the one of the cells within its
controlling cluster will force the network node to reverse those changes. For example, if
the change in transmission power is to reduce wireless coverage, this reduction cannot
occur if any cells within the cluster object. As mentioned above, once the reduction in
wireless coverage has been made, any request coming from any cell within the
controlling cluster will force the sleeping cell to restore its coverage.
In one existing technique, used for configuring the power consumption characteristics
of base stations, each base station is empowered to switch off autonomously. Using this
technique, the base stations autonomously decide to switch themselves off during
periods of, for example, low traffic activity. They then simply inform the other
surrounding base stations that they have switched off or want to switch off. When one
of the neighbouring base stations would like that base station to switch on again or
doesn't accept that it should switch off, it sends a request to the sleeping cell to switch
on again or not switch off and the sleeping cell can then accept that request or not. In
other words, each base station is in full control of itself and decides to switch off without
asking permission from the surrounding base stations and it decides whether or not to
accept a request to switch on again itself.
This approach is not optimal because the base station that switches itself off may not
have sufficient information regard the status of the neighbouring cells and their
autonomous switch off may then create resources issues in a neighbouring cell. Also,
once switched off, should any neighbour need assistance, (for example due to
overload or some network failure) it cannot be certain that the sleeping cell will react
positively to a request to switch on again to solve this difficultly.
In one embodiment, the proposed change is a switching off of wireless
communications coverage provided to user equipment by the network node.
Accordingly, should a power saving scheme be implemented in which network nodes
attempt to switch off whenever possible in order to conserve power, the network nodes
cannot switch off without asking permission from all network nodes in its controlling
cluster. Should any of the network nodes within the controlling cluster object to the
switching off, then the switch off cannot occur. Thereafter, once the changes are
made, any request coming from the network nodes within its controlling cluster will
force the network node to switch back on again.
In one embodiment, the proposed change is a switching of transceivers within the
network node. Accordingly, should a network node wish to switch o n or off its
transceivers in order to change the wireless characteristics of the network node, then
these are notified to the other network nodes within the controlling cluster prior to that
switching taking place.
In one embodiment, upon receipt of a n indication from one of said other network
nodes within the network node controlling cluster requesting reinstatement of wireless
communications coverage provided to user equipment by the network node, reversing
changes made to the characteristics of the network node to restore wireless
communications coverage provided to user equipment by the network node.
In one embodiment, the proposed change comprises a change in capacity of the
network node.
In one embodiment, the proposed change is a change in radiation levels output by the
network node.
In one embodiment the proposed change is a change in interference levels caused
by the network node.
In one embodiment, the network node controlling cluster comprises neighbouring
network nodes of the network node. Accordingly, the cluster may comprise network
nodes such as, for example, other macro base stations, micro base stations, femto base
stations, pico base stations, etc.
In one embodiment, the network node provides local wireless communications
coverage within wider wireless communications coverage provided by at least another
network node and the controlling cluster comprises the at least another network node.
Accordingly, the network may provide coverage within an overlaying umbrella cell. For
example, the network node may be a femto base station within a macro cell. In this
particular simple example, the cluster can be defined as being limited to the umbrella
macro cell. In embodiments, therefore, the femto base station will only switch off if the
umbrella macro base station does not object and will switch back on again as soon as
the macro base station requests. The macro base station therefore becomes more or
less in control of the sleeping mode of the femto base station. It should be noted that in
previous techniques mentioned above, the opposite would have resulted, the femto
base station would have been in control of itself regardless of the preference of the
macro base station.
In one embodiment, the network node controlling cluster comprises network nodes of a
differing radio access technology. Accordingly, the clusters may span network nodes
from 2G, 3G and/or 4G or other technologies.
In one embodiment, the network node controlling cluster is a cluster of clusters.
Accordingly, groups of clusters can be put together and any network node within the
larger group may object to the proposed changes being made.
In one embodiment, the network node comprises a base station.
According to a second aspect, there is provided a network node, comprising: logic
operable to identify at least one proposed change to said network node; and
characteristic change logic operable, in the absence of an indication from other
network nodes within a predefined network node controlling cluster for said network
node rejecting said at least one proposed change to said characteristics of said
network node, to subsequently make said at least one proposed change to said
characteristics of said network node.
In one embodiment, the logic comprises: notifying logic operable, upon determining a
proposed change to characteristics of the network node, to provide a first indication of
the proposed change to said other network nodes within said predefined network
node controlling cluster for the network node ; and said characteristic change logic is
operable, in the absence of said second indication from the other network nodes within
the network node controlling cluster rejecting the proposed change to the
characteristics of the network node, to subsequently make the proposed change to
the characteristics of the network node.
In one embodiment, the notifying logic is operable to provide the first indication by
transmitting a message indicating the proposed changes to the other network nodes.
In one embodiment, said logic is operable to identify said at least one predetermined
proposed change that may be made by said network node to said network node and
said other network nodes within said predefined network node controlling cluster for
said network node; and said characteristic change logic is operable to subsequently
make said at least one predetermined proposed change only when all other network
nodes within said network node controlling cluster have each provided a second
indication agreeing to said at least one predetermined proposed change.
In one embodiment, the characteristic change logic is operable, upon receipt of the
indication from the one of the other network nodes within the network node cluster
rejecting the proposed change to the characteristics of the network node, to abandon
the proposed change to the characteristics of the network node.
In one embodiment, the characteristic change logic is operable, upon receipt of the
second indication from all the other network nodes within the network node controlling
cluster accepting the proposed change to the characteristics of the network node, to
make the proposed change to the characteristics of the network node.
In one embodiment, the characteristic change logic is operable, upon receipt of a
third indication from one of the other network nodes within the network node
controlling cluster requesting reinstatement of the characteristics of the network node,
to reverse changes made to the characteristics of the network node.
In one embodiment, the third indication from a network node within the network node
cluster requesting reinstatement is received in a message from that network node.
In one embodiment, the proposed change is a change in transmission power of the
transceivers.
In one embodiment, the proposed change is a switching off of wireless
communications coverage provided to user equipment by the network node.
In one embodiment, the proposed change is a switching of transceivers within the
network node.
In one embodiment, the characteristic change logic is operable, upon receipt of an
indication from one of the other network nodes within the network node controlling
cluster requesting reinstatement of wireless communications coverage provided to user
equipment by the network node, to reverse changes made to the characteristics of the
network node to restore wireless communications coverage provided to user
equipment by the network node.
In one embodiment, the proposed change comprises a change in capacity of the
network node.
In one embodiment, the proposed change is a change in radiation Ievels output by the
network node.
In one embodiment, the proposed change is a change in interference Ievels caused
by the network node.
In one embodiment, the network node controlling cluster comprises neighbouring
network nodes of the network node.
In one embodiment, the network node provides local wireless communications
coverage within wider wireless communications coverage provided by at least another
network node and the controlling cluster comprises the another network node.
In one embodiment, the network node controlling cluster comprises network nodes of a
differing radio access technology.
In one embodiment, the network node controlling cluster is a cluster of clusters.
In one embodiment, the network node comprises a base station.
According to a third aspect, there is provided a method of controlling a network node,
comprising the steps of: identifying at least one proposed change to a network node;
determining whether said proposed change is likely to cause said network node to fail
to achieve quality of service requirements; and providing an indication to said another
network node rejecting said proposed change to said characteristics when it is
determined that said proposed change is likely to cause said network node to fail to
achieve quality of service requirements.
In one embodiment, the step of identifying comprises the step of: receiving a first
indication of a proposed change to characteristics of said network node.
According to a fourth aspect there is provided a network node, comprising:
identification logic operable to identify at least one proposed change to a network
node; characteristic change determination logic operable to determine whether said
proposed change is likely to cause said network node to fail to achieve quality of
service requirements; and rejection logic operable, in response to an indication from
characteristic change determination logic that said proposed change is likely to cause
said network node to fail to achieve quality of service requirements, to provide an
indication to said another network node rejecting said proposed change to said
characteristics.
In one embodiment the logic is operable to receive a first indication of a proposed
change to characteristics of another network node.
According to a fifth aspect of the present invention, there is provided a computer
program product operable, when executed on a computer, to perform the method
steps of the first or third aspect.
In one embodiment each network node within the cluster provides a status indication
of one of allowed and disallowed to a network node being controlled regarding
proposed change to the characteristics of that network node.
In one embodiment the status indication of disallowed aims to prevent the network
node being controlled from changing characteristics or aims to restore a characteristic
of the network node.
In one embodiment a network node being controlled is operable to receive a status
indication of one of allowed and disallowed from another network node belonging to a
cluster of one or several other network nodes whereby the network node is allowed to
change its characteristics only in case it has received a status indication of allowed
from all the network nodes that belong to the cluster.
In one embodiment, a network node being controlled is operable to receive a status
indication of one of allowed and disallowed from another network node belonging to a
cluster of one o r several other network nodes whereby the said network node is
prompted and triggered to restore a characteristic a s soon a s it receives the status
indication of disallowed from at least one of the network nodes that belong to the
cluster.
Further particular and preferred aspects are set out in the accompanying independent
and dependent claims. Features of the dependent claims may be combined with
features of the independent claims a s appropriate, and in combinations other than
those explicitly set out in the claims.
BRIEF DESCRIPTION OFTHE DRAWINGS
Embodiments of the present invention will now be described further, with reference to
the accompanying drawings, in which:
Figure 1 illustrates a n example arrangement of network nodes according to one
embodiment;
Figure 2 illustrates a n arrangement of a network node such as, for example, a base
station according to one embodiment; and
Figures 3, 4 and 5 illustrate a n example signal arrangement utilised by network nodes
within a cluster according to one embodiment.
DESCRIPTION OFTHE EMBODIMENTS
Figure 1 illustrates a n example arrangement of network nodes according to one
embodiment. In this arrangement, the network nodes are each base stations, although
it will be appreciated that the present technique is also applicable to other types of
network nodes. Each base station supports a corresponding cell. For example, in
Figure 1, there are provided six macro cells ( 1 to 6), each of which is supported by a
corresponding macro cell base station. Likewise, there are provided 5 femto cells (7 to
21), each of which is supported by a corresponding femto base station. It will be
appreciated that other sized cells, such a s micro o r pico cells may also be provided
supported by corresponding base stations which may also utilise the present technique.
Also, all of these cells need not necessarily utilise the same radio access technology
and instead may utilise different radio access technologies (for example, the some of
the macro base stations may be 3G, but some of the femto base stations may be 4G).
Each of the base stations is associated with a controlling cluster. Furthermore, each
base station may be associated with more than one controlling cluster. A cluster is an
arrangement of associated base stations. As will be explained in more detail below,
base stations associated with a cluster advise other base stations within that cluster of
any proposed changes to their characteristics. The base stations within the controlling
cluster collectively act asa "master" to the "slave" base station. In particular, a base
station can not make a change to its characteristics without the agreement (either
explicitly or implicitly) from all the base stations within the controlling cluster and must
reverse any changes made should any one of the base stations within the controlling
cluster request.
Various different cluster arrangements are possible. For example, it is possible to cluster
base stations of the same type, of different types, neighbouring or non-neighbouring,
irrespective of the radio access type associated with that base station. Furthermore, it
is possible to cluster smaller clusters together to form larger clusters. One example
cluster arrangement may comprise all the other femto base stations within a macro
cell. For example, one controlling cluster for the femto base station associated with
femto cell 17 may comprise the femto base station associated with femto cell 18 in
macro cell 4 . Likewise, another example controlling cluster may comprise only the base
stations appearing within the neighbour list of a particular base station. For example,
one controlling cluster for the femto base station associated with femto cell 7 may
comprise the femto base stations associated with femto cells 8 to 10 or for the macro
base station associated with macro cell 1may comprise the macro base stations
associated with macro cells 2 and 4. Likewise, another example controlling cluster may
comprise a base station associated with a cell located within another cell. For
example, a controlling cluster for the femto base station associated with femto cell 12
may comprise the macro base station associated with macro cell 2 . Such controlling
clusters, when utilised to determine whether a base station may be allowed to switch
off or enter a sleeping mode, will be described hereinafter as an "equivalent sleeping
cluster".
Figure 2 illustrates an arrangement of a network node such as, for example, a base
station 30 according to one embodiment. The base station 30 maintains a
characteristics table 40 indicative of the characteristics of that base station 30. For
example, the characteristics table 40 may comprise information on the operative state
of the base station 30, the status of the base station's transceivers, the power level of
those transceivers, the capacity of the base station, the radiation of levels of the base
station, or any other operative characteristics.
Change logic 50 is provided which is operable to determine that changes to these
characteristics may be necessary in order to, for example, save power, change the
capacity of the base station 30, reduce interference, reduce radiation emitted, etc.
The change logic 50 determines a proposed change to the characteristics of the base
station 30 and utilises notification logic 60 to provide details of these proposed changes
to other network nodes within that base station's cluster, as will be set out in more detail
below.
The other network nodes within the controlling cluster has similar logic provided therein
and receive that notification of the proposed change using their reception logic 70.
The proposed change is then passed to determination logic 80 which assesses the
impact of those changes based on information available to that network node. For
example, if the network node is only able to assess the impact of the changes on itself,
then the determination logic 80 assesses the impact of the proposed changes on that
network node and determines whether those changes would be acceptable. For
example, the determination may model characteristics of the network node using
information it has on the user equipment of which it is aware and an estimated service
requirement of that user equipment, and then determine whether those service
requirements or any quality of service requirements can still be met with the changes
proposed to the base station 30 within its cluster. The result of that determination may
then be communicated back to the originating base station, a s will also be described
in more detail below.
Should the originating base station 30 not receive a notification indicating that the
proposed changes are unacceptable to network nodes within the controlling cluster,
then that base station may implement those changes when convenient and update its
characteristics table 40 when the changes have been made. Alternatively, the
originating base station 30 may be configured only to make the proposed changes
once it receives a positive indication from the other network nodes within its cluster. If
any of the network nodes within the controlling cluster reject the changes, then the
base station 30 will abandon the proposed changes.
Typically, the base station 30 also retains information on the original characteristics
which have been changed. Should any network node within the cluster subsequently
determine that the changes are no longer acceptable because that network node is
now having difficulty achieving its service requirements or quality of service levels or
because of other network considerations, that network node may then signal the base
station 30 requesting that it reverses the changes made. On receipt of that message,
the base station 30 restores the characteristics to their original value.
For example, base stations within a cluster may have an energy saving requirement
requiring them to switch off their cells whenever possible in order to reduce power
consumption. The base stations within the cluster form a n equivalent sleeping cluster.
Should a base station determine that it is able to switch off coverage because, for
example, it is not currently supporting any user equipment, the proposed switching off
of the cell coverage is communicated to other base stations within the equivalent
sleeping cluster. Should any of those other base stations realise that switching off the
cell will cause unacceptable detriment to other base stations or to user equipment then
that base station will signal the base station proposing to switch off and prevent the
switch off from occurring. Likewise, should a base station within the controlling cluster
detect that such detriment starts to occur sometime after the base station has switched
off, the base station can be signalled to switch back on again and the inactive base
station must comply.
Figures 3, 4 and 5 illustrate a n example signal arrangement utilised by network nodes
within a controlling cluster. In this example, all messages are sent over the X2 interface
for intra-LTE communications. However, it will be appreciated that other signally
interfaces may be used for other architectures or technologies.
Figure 4 illustrates the arrangement where base station ENBl determines that it wishes to
switch off and sends a sleeping request message to base station ENB2 and base station
ENB3 (which are within the equivalent sleeping cluster for base station ENBl). Both base
station ENB2 and base station ENB3 determine that is it acceptable for base station
ENBl to switch off and so they both send a message to base station ENBl indicating
that the switch off is acceptable. On receipt of those messages from the base stations
with the equivalent sleeping cluster, base station ENBl then switches off.
Figure 4 illustrates a similar arrangement to Figure 3 . However, in this arrangement, base
station ENB3 determines that the switch off of base station ENBl would be
unacceptable. Accordingly, base station ENB3 sends a message to base station ENBl
indicating that the switch off is not acceptable. Accordingly, on receipt of that
message, base station ENB1 abandons the proposed switch off and instead stays
active.
Figure 5 illustrates the operation of a network node within the controlling cluster which
wishes to subsequently reverse a change that has been made to the network node it
controls. In this example, base station ENB1 has previously been switched off. When
the switch off occurred, none of the base stations within the equivalent sleeping cluster
considered the switch off to be unacceptable. However, base station ENB3 now
determines that it is necessary for the inactive base station ENB1 to switch back on
again. Accordingly, a wake up message is sent from base station ENB3 to base station
ENB1 . On receipt of that wake up message, base station ENB1 switches back on.
In another arrangement, particular predetermined configurations for the network nodes
are pre-identified in both the network node itself and those network nodes forming the
controlling cluster. For example, it may be an objective or policy of a network node to
switch off whenever it is not required by the network nodes of its controlling cluster. This
might occur when the network node is only provided to give additional capacity to
those network nodes in the controlling cluster when required. Of course, it will be
appreciated that other objectives such as reducing interference, reducing emissions,
maximising quality of service, etc may be pre-identified.
In this arrangement, each of the network nodes within the controlling cluster may
continuously or periodically determine whether they can achieve particular service
levels or quality of service requirements should the characteristics of the network node
being controlled change to meet those objectives in a similar manner to that indicated
above. In other words, each of the network nodes within the controlling cluster
determines whether these changes to the network node being controlled would be
acceptable.
The outcome of that determination may then be indicated to the network node being
controlled either actively or passively. For example, each network node within the
controlling cluster may indicate only when the changes would be acceptable to that
network node, indicate only when the changes would be not acceptable to that
network node or may indicate both.
When the network node identifies that every network node within its controlling cluster
has indicated that a change to its characteristics may be made, the network node can
then determine whether or not to make those changes to its characteristics.
Through this approach, it can be seen that no indication need necessarily be provided
from the network node being controlled each time a change to its characteristics is
desired. Instead, the network nodes within the controlling cluster may monitor
themselves whether those changes could be made and identify to the network node
being controlled when they consider that such a change is possible.
Of course, in a similar manner to that described above, should any network node within
the controlling cluster determine that those changes need to be reversed, this can be
indicated to the network node who must comply and reverse those changes.
Hence, each slave has a network cluster with one or more masters and may operate in
the following way: in order for a change to take place in the slave, the latter must
receive approval from all the "masters" of the cluster; any "master" in the cluster may at
every moment revoke its approval, and the "slave" shall then return to the initial
configuration. If a binary transition arrangement is considered (e.g. "on" / "off ), the
masters could automatically send their approval once permitted by the operating
conditions (load). Vice versa, the masters may automatically revoke their approval
when needed. Similarly: all the nodes of the controlling cluster may only provide an upto-
date status "allowed, not allowed" to the slave they control to say if they allow or
not the change in the slave; whenever the slave wants to make its change, it can only
make it if the current status from all the controlling cluster nodes are at "allowed"; later
on, if the change has been made, upon reception of a single status set to "disallowed",
the slave must come back to the original configuration.
Accordingly, it can be seen that a technique is provided which enables characteristics
of network nodes to be changed in a safe and cooperative manner. This enables
each network node to make its own assessment of changes that could be made, but
enables the impact of those changes to be assessed locally by a n appropriate cluster
of network nodes. This avoids the need for the configuration of every network node to
be provisioned centrally, which reduces complexity of the core network and the
signalling that would otherwise be required to enable the core network to make such
changes. Also, the cooperative nature of the technique prevents one network node
making a change which would be to the unacceptable detriment of other network
nodes. In particular, the present technique provides a safer energy saving solution in a
flat, distributed ran network such as a n LTE network. This provides power saving benefits
to the operator and cuts overall CO2 emissions.
A person of skill in the art would readily recognize that steps of various above-described
methods can be performed by programmed computers. Herein, some embodiments
are also intended to cover program storage devices, e.g., digital data storage media,
which are machine or computer readable and encode machine-executable or
computer-executable programs of instructions, wherein said instructions perform some
or all of the steps of said above-described methods. The program storage devices may
be, e.g., digital memories, magnetic storage media such as a magnetic disks and
magnetic tapes, hard drives, or optically readable digital data storage media. The
embodiments are also intended to cover computers programmed to perform said
steps of the above-described methods.
The functions of the various elements shown in the Figures, including any functional
blocks labelled as "processors" or "logic", may be provided through the use of
dedicated hardware aswell as hardware capable of executing software in association
with appropriate software. When provided by a processor, the functions may be
provided by a single dedicated processor, by a single shared processor, or by a
plurality of individual processors, some of which may be shared. Moreover, explicit use
of the term "processor" or "controller" or "logic" should not be construed to refer
exclusively to hardware capable of executing software, and may implicitly include,
without limitation, digital signal processor (DSP) hardware, network processor,
application specific integrated circuit (ASIC), field programmable gate array (FPGA),
read only memory (ROM) for storing software, random access memory (RAM), and non
volatile storage. Other hardware, conventional and/or custom, may also be included.
Similarly, any switches shown in the Figures are conceptual only. Their function may be
carried out through the operation of program logic, through dedicated logic, through
the interaction of program control and dedicated logic, or even manually, the
particular technique being selectable by the implementer as more specifically
understood from the context.
It should be appreciated by those skilled in the art that any block diagrams herein
represent conceptual views of illustrative circuitry embodying the principles of the
invention. Similarly, it will be appreciated that any flow charts, flow diagrams, state
transition diagrams, pseudo code, and the like represent various processes which may
be substantially represented in computer readable medium and so executed by a
computer or processor, whether or not such computer or processor is explicitly shown.
The description and drawings merely illustrate the principles of the invention. It will thus
be appreciated that those skilled in the art will be able to devise various arrangements
that, although not explicitly described or shown herein, embody the principles of the
invention and are included within its spirit and scope. Furthermore, all examples recited
herein are principally intended expressly to be only for pedagogical purposes to aid the
reader in understanding the principles of the invention and the concepts contributed
by the inven†or(s) to furthering the art, and are to be construed as being without
limitation to such specifically recited examples and conditions. Moreover, all statements
herein reciting principles, aspects, and embodiments of the invention, as well as
specific examples thereof, are intended to encompass equivalents thereof.
CLAIMS
. A method of controlling a network node, comprising the steps of:
identifying, to said network node and other network nodes within a predefined
network node controlling cluster for said network node, at least one proposed change
to said network node; and
in the absence of an indication from said other network nodes within said
network node controlling cluster rejecting said at least one proposed change to said
characteristics of said network node, subsequently making said at least one proposed
change to said characteristics of said network node.
2. The method of claim 1, wherein said step of identifying comprises:
upon determining a proposed change to characteristics of said network node,
providing a first indication of said proposed change to said other network nodes within
said predefined network node controlling cluster for said network node and said step of
making comprises:
in the absence of said indication from said other network nodes within said
network node controlling cluster rejecting said proposed change to said characteristics
of said network node, subsequently making said proposed change to said
characteristics of said network node.
3. The method of claim 1, wherein said step of identifying comprises:
identifying, to said network node and said other network nodes within said
predefined network node controlling cluster for said network node, said at least one
predetermined proposed change that may be made by said network node, ; and said
step of making comprises:
subsequently making said at least one predetermined proposed change only
when all other network nodes within said network node controlling cluster have each
provided a second indication agreeing to said at least one predetermined proposed
change.
4 . The method of any preceding claim, comprising the step of:
upon receipt of a third indication from one of said other network nodes within
said network node controlling cluster requesting reinstatement of said characteristics of
said network node, reversing changes made to said characteristics of said network
node.
5 . The method of any preceding claim, wherein said proposed change is at least
one of a change in transmission power of said transceivers, a switching off of wireless
communications coverage provided to user equipment by said network node, a
switching of transceivers within said network node, a change in capacity of said
network node, a change in radiation levels output by said network node, and a
change in interference levels caused by said network node.
6 . The method of any preceding claim, wherein said network node controlling
cluster comprises at least one of neighbouring network nodes of said network node,
network nodes of differing radio access technologies, and a cluster of clusters.
7. The method of any preceding claim, wherein said network node provides local
wireless communications coverage within wider wireless communications coverage
provided by at least another network node and said controlling cluster comprises said
at least another network node.
8. A network node, comprising:
logic operable to identify at least one proposed change to said network node;
and
characteristic change logic operable, in the absence of an indication from
other network nodes within a predefined network node controlling cluster for said
network node rejecting said at least one proposed change to said characteristics of
said network node, to subsequently make said at least one proposed change to said
characteristics of said network node.
9 . The network node of claim 8, wherein said logic comprises:
notifying logic operable, upon determining a proposed change to
characteristics of said network node, to provide a first indication of said proposed
change to said other network nodes within said predefined network node controlling
cluster for said network node; and said
characteristic change logic is operable, in the absence of said indication from
said other network nodes within said network node controlling cluster rejecting said
proposed change to said characteristics of said network node, to subsequently make
said proposed change to said characteristics of said network node.
10 . The network node of claim 8, wherein said logic is operable to identify said at
least one predetermined proposed change that may be made by said network node;
and said characteristic change logic is operable to subsequently make said at least
one predetermined proposed change only when all other network nodes within said
network node controlling cluster have each provided a second indication agreeing to
said at least one predetermined proposed change.
11. A method of controlling a network node, comprising the steps of:
identifying at least one proposed change to a network node;
determining whether said proposed change is likely to cause said network node
to fail to achieve quality of service requirements; and
providing an indication to said another network node rejecting said proposed
change to said characteristics when it is determined that said proposed change is likely
to cause said network node to fail to achieve quality of service requirements.
12. The method of claim 11, wherein said step of identifying comprising the step of:
receiving a first indication of a proposed change to characteristics of said
network node.
13. A network node, comprising:
identification logic operable to identify at least one proposed change to a
network node;
characteristic change determination logic operable to determine whether said
proposed change is likely to cause said network node to fail to achieve quality of
service requirements; and
rejection logic operable, in response to an indication from characteristic
change determination logic that said proposed change is likely to cause said network
node to fail to achieve quality of service requirements, to provide an indication to said
another network node rejecting said proposed change to said characteristics.
14. The network node of claim 13, wherein said logic is operable to receive a first
indication of a proposed change to characteristics of another network node
15. A computer program product operable, when executed on a computer, to
perform the method steps of any one of claims 1to 7, 11and 12.