GB2477261A

GB2477261A - Wireless transmission of a data file to a utility smart meter

Info

Publication number: GB2477261A
Application number: GB0918941A
Authority: GB
Inventors: Philip Handley
Original assignee: ARQIVA Ltd
Current assignee: ARQIVA Ltd
Priority date: 2009-10-28
Filing date: 2009-10-28
Publication date: 2011-08-03
Also published as: GB0918941D0

Abstract

A communications system 10 to wirelessly transmit a data file 17, 19, 21 to a network node 50, the system comprising: a higher bandwidth first communications channel 30 for transmitting data; a second cellular communications channel 40 to transmit and receive data, the channel capacity of the second communications channel 40 being less than the channel capacity of the first communications channel 30; broadcasting over the first communications channel 30, a data file 17, 19, 21, to be received by at least one network node 50; confirming whether or not the data file was received over the second communications channel 40; and if not, broadcasting the data file to the network node 50 over the second communications 40 channel. Can be used in a telemeter environment for updating software, firmware or tariff information to utility smart meters. First network may be Digital Audio Broadcast (DAB). Second network may be Long Range Radio (LLR).

Description

WIRELESS COMMUNICATIONS SYSTEM AND METHOD

TECHNICAL FIELD

The invention relates to a wireless communication system and method to wirelessly transmit a data file to a network node. The system and method of the invention find particular, though not exclusive, utility in the operation of a smart metering system and downloading software to a large number of smart meters.

BACKGROUND OF THE INVENTION

Monitoring residential, commercial and industrial consumption of resources provided by utilities (such as electricity grid supply, gas and water) for billing and demand-monitoring purposes has, in the past, been achieved by measuring consumption at the point of use with simple meters from which readings are taken at the point of use at intervals.

Recently, however, a number of factors have generated significant interest in the replacement of these simple meter monitoring systems with recently proposed smart metering systems in which smart meters measure resource consumption at the point of use and can automatically communicate this usage to the resource supplier almost in real-time via a suitable communication path.

This smart metering provides benefits to utility providers by providing automated meter readings, improving billing accuracy, enabling leak detection, and, significantly, monitoring demand in real time, which is particularly important in times of scarce resources and when resource supply is not guaranteed. Further, detailed resource usage information can then be provided to utilities users such that end users can monitor their usage and change their behaviour, which is of particular interest in times when increased power economy is a concern. Smart metering also enables more dynamic operation of utility provision such as permitting accurate pre-paid metering, tariff adjustment, providing usage alerts to users and reactive power management both on the supply side and the demand side. Smart metering systems are also integral to the operation of a smart electricity supply grid.

The exact mode of deployment and operation of such smart metering systems is largely to be determined on a national or regional basis and may at least be influenced by existing infrastructure, government schemes and tendering, and established standards. One aspect of the smart metering system of fundamental operational importance is the communication system and method for transferring data to and from the utility suppliers and the numerous smart meters which are likely to be spread across a large geographical area.

Two such smart metering communication systems that have been proposed, at least for residential smart metering, are shown in Figures la and lb. Figure la shows an arrangement of a communications system 1 a according to a transport model' in which concentration of the various communication networks used occurs outside individual houses. Figure lb shows an alternative or complementary arrangement of a communications system lb according to a consumer centric model' in which concentration of the various communication networks used occurs inside individual houses.

In Figure 1 a, smart metering information systems 2, which operate to send and gather data from residential smart meters 3 on behalf of utility service providers and utility network operators, etc., are connected via at least one Wide Area Network (WAN A, WAN B) to communicate with a plurality of concentrators 5.

Each concentrator is arranged to act as a network gateway for a Local Area Network (LAN) to which there are connected a number of residential units 7 (i.e. utility resource consunlers), and as a protocol converter between the at least one WAN and the LAN to which it is connected. The LAN may be any less-than-lkm range wired or wireless network (for example, a wireless network based on a short range radio protocol or M-bus). Each LAN has connected to it a plurality of smart meters 3 arranged in residential units 7 to measure the consumption of a utility resource (e.g. electricity, water or gas) therein. The smart meters 3 communicate with the concentrator 5 via the LAN (e.g. using short range radio transceivers), which routes data over the WAN to the smart metering information systems, and vice-versa.

The communications system lb shown in Figure lb is similar to that shown in Figure 1 a, except that, in this arrangement, a residential communications gateway 9, such as a modem]router, is provided in a Home Area Network (HAN) of a single residential unit 7. The residential communications gateway 9 is configured to send and receive data between the local smart meters 3 connected to the HAN and the smart metering information systems, over the WAN. Also connected to the HAN may be other miscellaneous local electronic devices, such as personal computers, laptops, domestic appliances, etc. The transport model shown in Figure 1 a and the consumer centric model shown in Figure lb may be combined such that, in a national or regional smart metering communications system, both models are used.

For the Wide Area Networks being operated in the smart metering communications systems shown in Figures 1 a and lb a number of different possibilities have been suggested, such as GPRS mobile phone communication between the concentrators/residential gateways and the smart metering information systems, or even the Internet.

In a typical national or regional deployment of a smart metering system a very large number of smart meters will be operated which need to send and receive data to and from the smart metering information systems. In normal operation and use of the smart metering system a steady volume of data has to be sent on the smart metering communications system to the smart metering information systems via a WAN in the form of meter readings and other low-volume data. Therefore a type of WAN having an appropriate data throughput or channel capacity corresponding to the normal requirements might typically be chosen to be provided in the smart metering communication system.

However, the present inventors have realised that the smart meter network operators and the utility suppliers will occasionally need to provide to the smart meters significantly larger amounts of data than that transferred during normal operation of the smart metering system. For example, utility providers or network operators may occasionally need to provide software to the smart meters, either as new software or a software update. Such software may provide the smart meters with updated firmware, tariff scheduling, functionality, etc. The transferring of such relatively large amounts of data to the smart meters over a relatively low capacity channel data link on a WAN may, in certain circumstances, not provide optimum efficiency of use of the system's resources.

It is therefore an object of the present invention to provide a communications system and method in which a number of geographically distributed end user units, such as smart meters, can be efficiently provided with a download of a relatively large data file.

SUMMARY OF THE INVENTION

Viewed from one aspect, the invention provides a method of operating a communications system to wirelessly transmit a data file to a network node, the communications system comprising: a first network of first base stations, each first base station having a wireless transmitter configured to transmit data over a first communications channel of the first network; a cellular second network of second base stations with a coverage area overlapping the coverage area of the first network of first base stations, each second base station having a wireless transceiver configured to transmit and receive data over a second communications channel or channels of the second network, the channel capacity of the or each second communications channel by which each second base station transmits data being less than the channel capacity of the first communications channel; and a plurality of network nodes dispersed throughout the first and second networks, each network node having wireless communication means capable of receiving data from a first base station over the first communications channel and capable of data communication with a second base station over a said second communications chaimel; the method comprising: broadcasting, from at least one of the first base stations over the first communications channel, a data file to be received by at least one network node; confirming whether or not the data file was received at one of the network nodes by initiating communication, over a said second communications channel, between that network node and the second base station of the relevant cell of the second network of second base stations; and if the data file was not received at that network node, broadcasting the data file to the network node from the second base station of the relevant cell over a said second communications channel.

The channel capacity of a network is the limiting information rate (in units of information per unit time) that can be achieved over a data channel on that network with a given arbitrarily small error probability. Channel capacity is related to the data throughput of a channel, which is the average rate of successful data delivery achievable on the channel. The two terms, while having different meanings, are intended to be usable interchangeably in this application. Similarly, channel data rate, or channel bandwidth can be used to describe the maximum data transfer rate obtainable with the Wide Area Networks used in the communications systems and methods of the invention.

In accordance with the invention, in addition to a cellular network of base stations having a communications channel or channels (which may be provided as, for example, a main transmission channel and a back-channel) which have a relatively low channel capacity for two-way data communications, which can be used for sending and receiving smart meter data in normal operation, another network of base stations is provided having a coverage area overlapping with the coverage area of the cellular network and having a relatively high channel capacity which is capable of one way data transmission to the network nodes. Thus, in the case when a data file (for example, a relatively large software update) is to be sent to a plurality of network nodes, the communications system can be operated to broadcast the data file on the relatively high channel capacity network. To ensure that any data file broadcast to the network nodes on the relatively high channel capacity network has been received, in accordance with the invention, the receipt of the data file at a network node is confirmed by communication with the network node over the relatively low channel capacity network. The initiation of this communication may be as a result of the network node being polled or queried, or the network node may automatically confirm whether or not the data file was received. Then, if the network node confirms that the data file was indeed not received, the data file is then re-sent to the network node from a base station of the relevant cell of the relatively low channel capacity network. Thus the invention provides a method of operating a communications system having relatively high and low channel capacity networks in which data file downloads can be performed quickly and efficiently using a relatively high channel capacity network, without having to rely on only the relatively low channel capacity network, the available bandwidth of which would otherwise have to be shared. Further, in accordance with the invention, the file downloads can be confirmed and efficiently completed for all network nodes.

The coverage of the cellular second network of second base stations may extend to locations outside the coverage of the first network of first base stations.

The coverage of the cellular second network of second base stations may be greater than the coverage of the first network of,first base stations. The coverage of the second network will typically extend almost continuously nationwide or across a region in order to provide a means of normal data communication with the network nodes. However, typically, in many practical situations the coverage of the relatively high channel capacity first network may not be continuous and may not extend to all areas covered by the second network (areas of patchy coverage may be, for example, rural areas). Thus, in these circumstances, high-speed data file downloads via the first network would not be available to network nodes across the whole area of service. The redundancy built in to the present invention provided by back-up' downloads via the relatively low channel capacity second network is therefore particularly advantageous where the coverage of the relatively high channel capacity network does not extend to provide data transmission to all -7.-network nodes to which a data file must be provided.

Preferably, only the second base stations of those cells of the cellular second network in which a network node has confirmed that the data file was not received, broadcast the data file to the network node over a said second communications channel. Alternatively, the network nodes may be configured to automatically confirm receipt of the data file and the communications system may then determine which network nodes did not receive the data file by checking whether the network node has transmitted a confirmation. In this alternative configuration, only the second base stations of those cells of the cellular second network in which a network node has not confirmed that the data file was received, broadcast the data file over a said second communications channel. Only re-sending the data file on the relatively low channel capacity network from base stations in cells in which the download was not received at a network node prevents wide-spread use of the relatively low channel capacity network for the purposes of large data file downloads. While counter intuitive, these preferred modes of operation are particularly advantageous since relatively low channel capacity network cells where the data download from the relatively high channel capacity network will not have been received will, in practical embodiments, typically be in relatively rural areas where the data throughput requirements on the relatively low channel capacity network in that cell will be significantly less than in urban areas. Thus, in this arrangement, data file download will usually be efficiently completed in urban areas using the relatively high channel capacity first network without having to use the relatively low channel capacity second network in those areas, and in certain rural areas, data file download may be completed using the relative low channel capacity second network, in which case the burden on the capacity of the second network will typically not be unacceptably high due to the low normal data throughput requirements in these areas.

The communications system may further comprise a local electronic device associated with a network node. At least one network node may be a concentrator or a communications gateway connected to a residential home area network (HAN) or local area network (LAN) to which there is connected at least one local electronic device, or the network node may be a local electronic device. In accordance with this arrangement of the invention, the communications system provides data communications with appropriate local electronic devices directly, or under the transport model or the consumer centric model.

The local electronic device may be configured to send a message on successful reception of a data file, and a database of devices can be used to identify failed downloads.

Alternatively, confirming whether or not the data file was received at a particular network node may comprise the steps of: operating a second base station to transmit an instruction to the network node in relation to the data file; and if the data file was not received at the network node, in response to receipt of the instruction at the network node, transmitting from the network node to the second base station data confirming that the data file was or was not received. The instruction sent to the network node in relation to the data file may be a software activation instruction. In accordance with this preferred method, the data file may be broadcast using the relatively high channel capacity network. To trigger the data file to be used at a network node, or at local electronic devices associated therewith, an instruction is sent to the network node (e.g. a software activation instruction).

Advantageously, the instruction may then be acted on in relation to the data file, or, if the data file was not received, a confirmation of receipt or non-receipt may be returned.

The local electronic device may be a smart meter for monitoring local usage of a utility service such as gas, water or electricity. The data file may be software for a smart meter. The invention finds a particularly advantageous application as a smart metering data communications method and system.

The communications system may further comprise a central server capable of operating the first and second networks of first and second base stations to send and receive data files to smart meters associated with the network nodes. The server may operate the first and second networks such that only software files are sent to smart meters using the first network, and such that all other data communication with the smart meters is performed using the second network. The central server, which may act as, for example, a smart metering information system in a smart metering communication system, may operate the system so as to perform normal data communications on the relatively low channel capacity network and only data file downloads on the relatively high channel capacity network. In this way, wide-spread use of the relatively low chamiel capacity first network for the purposes of data file downloads is avoided.

In this preferred arrangement, the data files may include target addresses such that, after the central server operates the first and second networks to broadcast the data files to all smart meters in range, only the targeted smart meters having a specified address will use the data file. As there may be many different types of smart meter deployed throughout the communications network, each requiring particular data files and software updates, the data file that is broadcast to all smart meters needs to be stored on selected smart meters such that only the desired smart meters are updated. In accordance with this preferred method, the data files themselves may include addressing data such that only selected smart meters will store that data file, and the remaining smart meters will ignore the download.

Alternatively, after the central server operates the first network to broadcast a data file, the central server may operate the second network to broadcast addressed software activation instructions to all smart meters to activate the software provided by the data file only on targeted smart meters having addresses specified in the activation instructions. When a smart meter receives an activation instruction for a data file it has not received, the network node associated with the smart meter may transmit data to the relevant second base station confirming that the data file has not been received. In this alternative preferred method, the addressing data is sent separately from the file using the relatively low channel capacity network such that only selected smart meters will store that data file. If a (selected) smart meter -10 -receives addressing information in relation to a data file that has not been received, then the smart meter may transmit (e.g. via the associated network node) over the lower channel capacity network a confirmation of non-receipt of the data file. The data file may then be re-sent to that smart meter over the lower channel capacity network.

The first network of first base stations may be a network of Digital Audio Broadcasting (DABIDAB+/DMB) radio transmitters and the first communications channel may be a Digital Audio Broadcasting communications channel. The second network of second base stations may be a cellular network of Long Range Radio (LRR) transceivers and the second communications channel may be a digital radio communications channel. DAB and LRR networks provide, respectively, particularly advantageous relatively high and relatively low channel capacity digital data communication channels, in particular for smart metering applications. The base station to network node bitrate provided on a single LRR channel is typically around 500 bit/s (whereas the network node to base station bitrate is typically even lower at around 63 bitls) and the download bitrate on a single DAB channel is variable up to typically 128 kbps.

Viewed from another aspect, the invention provides a communications system for wirelessly transmitting a data file to a network node, comprising: a first network of first base stations, each first base station having a wireless transmitter configured to transmit data over a first communications channel of the first network; a cellular second network of second base stations with a coverage area overlapping the coverage area of the first network of first base stations, each second base station having a wireless transceiver configured to transmit and receive data over a second communications channel or channels of the second network, the channel capacity of the or each second communications channel by which each second base station transmits data being less than the channel capacity of the first communications channel; and a plurality of network nodes dispersed throughout the first and second networks, each network node having wireless communication means capable of receiving data from a first base station over the first communications channel and capable of data communication with a second base station over a said second communications channel; wherein the first network of first base stations is configured to be operable to broadcast a data file to be received by the network nodes over the first communications channel; wherein each network node is configured to be able to confirm whether or not the data file was received at that network node by communication over a said second communications channel with the second base station of the relevant cell of the second network of second base stations; and wherein the second network of second base stations is configured to broadcast the data file over a said second communications channel in those cells where network node confirms that a data file is not received at that network node.

The various preferred features of the first aspect of the invention are also applicable to the second aspect, either individually or in combination. Further, the above-described advantages of the first aspect of the invention are also provided by the second aspect of the invention.

In accordance with further aspects of the invention, there is provided a smart meter, a communications gateway, a concentrator and a server, and various computer program products each being as set out in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

Certain preferred embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figures Ia and lb are schematic representations of smart metering systems showing two possible arrangements of communications systems for smart metering; Figure 2 is a schematic representation of a smart metering system including an embodiment of the architecture of the communications system of the invention; and Figure 3 is a schematic representation showing the coverage provided by an arrangement of a networks of first and second base stations according to an embodiment of the communications system of the invention.

-12 -

DESCRIPTION OF THE EMBODIMENTS

Figure 2 shows a schematic representation of a smart metering system including a communication system 10 in accordance with the invention. The communication system 10 provides data communication between a central server 11 and a plurality of local electronic devices 13a, 13b, 13c,... 13f. In this embodiment the local electronic devices 13a, 13b, 13c,... 13f are provided as smart meters in residential, industrial or commercial units, which are each arranged to monitor local consumption of some utility resource (e.g. electricity, gas or water).

The central server 11 is arranged to access and update a database 15 of data files for downloading to the plurality of smart meters 13a, l3b, 13c,... 13f Data files stored in the database 15 may be in the form of sofiware (for example, firmware updates for a specific type of smart electricity meter operated by a particular meter operator and installed only in certain residential units). The data files may be uploaded directly to the server 11 by energy suppliers 17, smart meter operators 19 or device managers 21. The data files may be assigned a priority for downloading to the smart meters 13a, 13b, 13c,... 13f and also may be associated with addressing information for instructing only smart meters having specified addresses to use that data file.

The central server 11 and the database 15 are comprised as part of a smart metering information system to communicate with smart meters 13a, l3b, 1 3c,...

1 3f and automatically obtain meter reading data, as well as provide data files to the smart meters 13a, 13b, 13c,... 13f.

Communications system 10, which provides data communication between the central server 11 and the smart meters 13a, 13b, 13c,... 13f, includes a first network 30 of first base stations and a second network 40 of second base stations, the second network 40 having a coverage area overlapping the coverage area of the first network 30. The first network 30 of first base stations is chosen as one that has a higher channel capacity (and/or data throughput and/or bandwidth) than the second network 40 of second base stations. In the communications system 10 shown in Figure 2, the first network 30 of first base stations is a Digital Audio Broadcast -13 -network of transmitters providing a one-way point-to-multipoint broadcast communications channel having a channel capacity, throughput or bandwidth of variable up to 128 kbitls. The second network 40 of second base stations may be a cellular network of Long Range Radio transceivers providing bi-directional point-to-multipoint communications over a communications channel and back-channel each having a channel capacity, throughput or bandwidth (from base station to network node) typically around 500 bit/s which is much less than the capacity provided by the DAB network. The cellular network of Long Range Radio transceivers may typically be implemented using base station radio modules operating low-power point-to-multipoint communications on a narrow band channel potentially with a high number of network nodes, in which a high bitrate has been sacrificed to provide long range, high-reliability data communications, over up to, for example, 20km (depending on local topography, etc). To provide two-way communication on the second network 40, a single two-way communications channel may be used, or multiple communications channels may be used. Backhaul from the cellular network base stations may be provided, for example, by a wired ADSL connection.

Figure 3 shows the arrangement of the first and second networks of the first and second base stations over a geographic area, and the coverage provided thereby.

The circular rings represent the geographical coverage provided by a single DAB transmitter at a first base station provided at the centre of each ring. The tessellated diamonds represent the geographical coverage provided by a single LRR transceiver of a second base station provided at the centre of each diamond. Of course, the circular and diamond shapes of the coverage of the DAB transmitters and the LRR transceiver cells shown in Figure 3 are provided only to schematically represent these networks arranged in accordance with the invention. Various cell shapes and coverage areas are possible in both networks and these are dependent on, for example, local topography. The actual coverage will be overlapping irregular shapes as is well known.

The LRR transceivers are arranged as a cellular network and provide full coverage and data communication in a desired geographical area for which a smart metering system is to be operated. The LRR network will thus typically extend to cover an entire nation or region throughout which there will be dispersed a number -14 -of residential, commercial or industrial units in which there is provided a number of smart meters 13a, 13b, 13c,... 13f. However, it is evident that the coverage provided by the network of DAB transmitters does not extend to all areas of the LRR cellular network. Indeed, DAB network coverage is typically first provided in relatively urban areas and may be scant or non-existent in relatively rural areas.

Further, in certain locations, DAB network coverage may be significantly impeded due to local topology or building construction and, so DAB reception may not be reliably provided even in more urban areas.

Communication between the central server 11 and the smart meters 13a, 13b, 13c,... 13f is provided by the transport model and/or the consumer centric model andlor by any other suitable arrangement.

Figure 2 shows the communications system having an exemplary residential local area network 50 in which communication with the smart metering system is operated under the transport model. As a network node in the residential local area network 50 a concentrator 51 is provided. The local area network 50 is a <1km network operating on a short range radio protocol wirelessly connecting to gateways 65a, 65b, such as residential gateways or routers of home area networks 60a, 60b.

The short range radio protocol may for example be the ZigBee radio protocol. The concentrator 51 includes a DAB receiver 53 to receive data communication directly from the server 11 via the DAB network 30 of first base stations (if coverage is available), and a LRR transceiver 55 to send and receive data communication to and from the server 11 via the LRR network 40 of second base stations. The concentrator 51 acts as a network node in the local area network 50 interfacing between the local area network 50 and the DAB network 30 and LRR network 40.

The concentrator 51 has a storage memory 57 for storing data received from the residential gateways 65a, 65b the DAB network 30 and the LRR network.

In each home area network 60a, 60b, respective smart meters 13a, 13b, l3c,... 13f are connected to residential gateways 65a, 65b by a wireless or wired network connection and communicate therewith by any appropriate communications protocol. Numerous other domestic andlor other appliances may also be connected to the residential gateways 65a, 65b of the home area networks 60a, 60b.

-15 -Normal operation of the smart metering system and communications system for monitoring consumption, transferring meter reading data, etc. (i.e. anything other than downloads of relatively large data files) will now be described.

Data, such as meter reading data, to be sent from the smart meters I 3a, I 3b, 13c,... 13f to the central server 11 is sent periodically in accordance with the meter settings of each smart meter (governed e.g. by software being run on the smart meters) via the respective residential gateways 65a, 65b of each home area network 60a, 60b to concentrator 51 using the local area network. This data may be stored locally at the concentrator 51 in storage memory 57 or may be passed on to the server 11 without storage. Backehannel communication between the concentrator 51 and server 11 is provided via the LRR network and the LRR transceiver 55 in the concentrator 50 transmits the meter reading data to the server 11. Meter readings received at the server 11 are then logged in database 15 and the energy suppliers 17 and smart meter operators 19 may then access the database to monitor usage, calibrate resource supply to demand, perform billing operations and assessments.

Similarly, messages (i.e. which comprise small amounts of data relating to the normal smart metering operations of the system) may be sent from the server 11 to the smart meters 13a, 13b, 13c,... 13f via the LRR network 55.

As only a relatively small amount of data is generated by the smart meters l3a, 13b, 13c,.,. 13f during normal operation of the smart metering system, the channel capacity required of a data channel to send and receive normal operational data between the smart meters 13a, 13b, l3c,... 13f is relatively low even where thousands of smart meters are located in one LRR cell. Thus a low channel capacity network, such as LRR, which provides a maximum information transfer rate of only typically around 500 bitls, can be chosen. As a result, the chosen network can be low power, long range and have low operational costs.

Operation of the smart metering system and communications system 10 for downloading data files (i.e. relatively large discrete amounts of data), will now be described.

Occasionally energy suppliers 17, smart meter operators 19 or device managers 21 will desire to send relatively large data files such as software (e.g. firmware updates) and other bulk data to the smart meters 13 a, 13 b, 1 3c,... 1 3f. For a moderately sized software update file of 100 kilobytes (kB) to be broadcast to the smart meters 13a, l3b, 13c,... 13f over the point-to-multipoint LRR network 40 having a channel capacity of only typically around 500 bit's it would take around 26 minutes. As there may be tens of different types and models each of which each need to be updated separately, it is clear that to transmit this volume of data over the LRR network 40 would perhaps require a significant level of use of the LRR network capacity and may take a considerable amount of time. Further, if priority were given to transfer of normal operational data (e.g. sending of messages and meter reading requests) over larger data files on the LRR network, then transfer of those data files may take even longer. This would particularly be the case in urban areas where the channel usage requirements during normal operation are relatively high (due to the density of residential units) compared to rural areas, thus giving little spare channel capacity for data file transfer.

Instead, large data files (e.g. software updates) are transmitted from the central server to the smart meters 13a, 13b, 13c,... 13f via the DAB network 30.

The DAB network 30, having a channel capacity of up to 128 kbitlsec (i.e. the maximum information transfer rate obtainable therewith), which is significantly higher than that of the LRR network, will broadcast a 100 kilobyte (kB) data file in only 6.4 seconds. Thus data file transmission over the DAB network can provide a quick and efficient means of providing downloads of relatively large data files to large numbers of distributed smart meters.

To transfer the data files the server 11 broadcasts the data (for example, as packet data) over the DAB network 30. If the concentrator 51 is located within the coverage range of a DAB transmitter of the DAB network 30 (for example, if the concentrator 51 is located in LRR cell 101 shown on Figure 3, which lies inside the range of a DAB transmitter) it will receive the data file from the central server 11 over the DAB network 30 using DAB receiver 53. The data file may be stored locally in the concentrator 51 in storage memory 57 or may be passed on immediately without storage. From the concentrator 51 the data file is sent via the local area network 50 to residential gateways 65a, 65b where the data file is then sent (e.g. by routing) to smart meters 13a, 13b, 13c,... 13f which may store or otherwise use the data.

However, if the concentrator 51 is located outside the coverage range of a DAB transmitter of the DAB network 30 (for example, if the concentrator 51 is located in LRR cell 102 shown in Figure 3, which lies outside the range of a DAB transmitter) it will not receive the data file.

After broadcasting of the data file over the DAB network 30 is complete, confirmation of receipt of the data file at the concentrator 51 is given by initiating communication with the concentrator 51 over the LRR network 40. The exact mode of this confirmation may vary and may depend on how the data files are distributed and their usage at smart meters initiated.

In one advantageous method, as there may exist in the smart metering system a number of different types of smart meters, or as a utility supplier may only want to update the software of particular smart meters (i.e. their own customers), addressing data may be incorporated into the system in relation to a data file. The addressing data associated with a data file may define which of the smart meters 13a, 13b, 13c,... 13f the data file is to be used on. Thus after broadcasting the data file over the DAB network 30, and after the concentrators 51 that received the file have stored the file in the local memory 57, the server sends out addressing data associated with the data file over the LRR network 40. All concentrators 51 would then receive the addressing data. If the concentrator 51 did receive the file over the DAB network, the concentrator would then send the data file to only the relevant smart meters 13a, 13b, 13c,... 13f identified in the addressing data and also send data back to the server 11 via the LRR network 40 confirming that the data file in question was received. (Alternatively the data file could initially be sent to all smart meters 1 3a, 1 3b, 1 3c,... 1 3f but later activated only in those smart meters identified in the addressing data, and deleted/ignored in all other smart meters.) However, if the concentrator 51 did not receive the data file it would then send data back to the server 11 via the LRR network 40 confirming that the data file in question was not received. Communication with the server would be via the local LRR transceiver cell of the cellular LRR network 40.

Alternatively, each network node that received the data file may signal receipt of the data file (e.g. automatically) and the central server 11 can then -18-determine (for example, by cross-referencing a database of network nodes and/or smart meters) which network node did not receive the data file.

Once the server 11 has identified all LRR cells in which the data file was not received it selectively re-sends the data file only via the LRR transceivers of those LRR cells such that the concentrators 51 (or other network nodes) located in those LRR cells would then receive the data file, albeit over a significantly longer time.

(Other LRR cells are not sent the file by the relevant second base stations.) However, in these LRR cells where data file downloads are completed using the LRR network, the required use of the LRR channel capacity for this purpose is in no way a burden because it is typically only relatively rural areas where DAB coverage does not extend. Thus the data requirements for normal operation of the smart metering system in these cells is much lower than the maximum LRR channel capacity, and thus the spare capacity can be efficiently used to transmit the data files Confirming via the LRR network 40 whether or not the data file was received via the DAB network 30 at a particular network node (e.g. concentrator or HAN gateway) may include only sending data confirmation back via the LRR network 40 if the data file was not received. It may be that no data confirmation is sent back from the network node if the data file was received via the DAB network 30.

By using the communications system of the invention the data file can be efficiently transmitted to all relevant smart meters in a large and geographically extensive smart metering system in good time. This is because the mix of a relatively high channel capacity network for primary data file broadcast (arranged particularly in urban areas) together with a relatively low channel capacity network for data transfer in normal operations and also secondary data file broadcast if necessary (particularly useful in rural areas) provides an optimum mix to address the problem of providing occasional data file downloads in a system that normally requires only a low transfer capacity.

While the specific description above, and the background to the invention describe the communications system in the context of smart metering, the communications system and method can equally be applied in other fields to offer -19 -the same benefits. Many different types of local electronic devices may conm-lunjcate with a central server in accordance with the invention via two communications channels such that data file downloads can be provided to the local electronic devices. The invention is particularly suitable for wirelessly communicating with a large number of electronic devices over a large geographical area where normally only a low data transfer rate is required, but occasional large data downloads must be performed. For example, the local electronic devices may be household white goods (e.g. fridges/freezers), a vehicle information system roviding information collection, for example for tax and insurance purposes), industrial monitoring and remote sensing (e.g. gas tank levels, septic tank levels, etc).

Alternative confirmation methods to that described above may be provided for in the communications system of the invention. For example, addressing information could be included in the data file itself such that, once it is broadcast over the DAB network 40, it is automatically only stored by the smart meters indicated in the addressing information, with all other smart meters ignoring the file.

Then only a triggering instruction (without addressing data) to cause the data file to become active (e.g. to activate the firmware update) would have to be sent over the LRR network 40. Then only those network nodes that did not receive the data file over the DAB network 40 would send back to the server 11 a confirmation that the data file was not received.

Alternatively, and/or in addition to the transport model arrangement shown in Figure 2, there may also be provided further local area networks (not shown) and home area networks (not shown) for further residential, commercial or industrial units. Communication with the smart metering system may be via the transport model and/or the consumer centric model and/or by any other suitable arrangement.

Under the consumer centric model the architecture for communicating between the smart meters and the DAB network 30 and LRR network 40 differs from that shown in Figure 2. In the consumer centric model gateways 65a, 65b provided in the home area networks 60a, 60b act as network nodes in the home area networks 60a, 60b that interface between the respective home area networks 60a, 60b and the DAB network 30 and LRR network 40. To achieve this the gateways -20 - 65a, 65b themselves include a DAB receiver to receive data communication directly from the server 11 via the DAB network 30 of first base stations (if coverage is available), and a LRR transceiver to send and receive data communication directly from the server 11 via the LRR network 40 of second base stations. In this model the gateways 65a, 65b interface directly between the home area networks and the DAB and LRR networks such that the concentrator 51 and local area network may not be necessary and might not be provided.

Alternatively, the smart meters may themselves interface directly with the DAB network 30 and LRR network 40. To achieve this the smart meters may include a DAB receiver to receive data communication directly from the server 11 via the DAB network 30 of first base stations (if coverage is available), and a LRR transceiver to send and receive data communication directly from the server 11 via the LRR network 40 of second base stations.

In the arrangement shown in Fig 2, DAB is provided as a high channel capacity one-way data link for downloading. However, a different architecture could be chosen to provide a bi-directional data channel as the relatively high channel capacity data link.

Claims

-21 -CLAIMSI. A method of operating a communications system to wirelessly transmit a data file to a network node, the communications system comprising: a first network of first base stations, each first base station having a wireless transmitter configured to transmit data over a first communications channel of the first network; a cellular second network of second base stations with a coverage area overlapping the coverage area of the first network of first base stations, each second base station having a wireless transceiver configured to transmit and receive data over a second communications channel or channels of the second network, the channel capacity of the or each second communications channel by which each second base station transmits data being less than the channel capacity of the first communications channel; and a plurality of network nodes dispersed throughout the first and second networks, each network node having wireless communication means capable of receiving data from a first base station over the first communications channel and capable of data communication with a second base station over a said second communications channel; the method comprising: broadcasting, from at least one of the first base stations over the first communications channel, a data file to be received by at least one network node; confirming whether or not the data file was received at one of the network nodes by initiating communication, over a said second communications channel, between that network node and the second base station of the relevant cell of the second network of second base stations; and if the data file was not received at that network node, broadcasting the data file to the network node from the second base station of the relevant cell over a said second communications channel.
2. A method as claimed in claim 1, wherein the coverage of the cellular second network of second base stations extends to locations outside the coverage of -22 -the first network of first base stations.
3. A method as claimed in claim 1 or 2, wherein the coverage of the cellular second network of second base stations is greater than the coverage of the first network of first base stations.
4. A method as claimed in claim 1, 2 or 3, wherein only those second base stations of cells of the cellular second network in which a network node has confirmed that the data file was not received broadcast the data file to the network node over a said second communications channel.
5. A method as claimed in claim 1, 2 or 3, wherein only those second base stations of cells of the cellular second network in which a network node has not confirmed that the data file was received broadcast the data file to the network node over a said second communications channel.
6. A method as claimed in any preceding claim, wherein the communications system further comprises a local electronic device associated with a network node.
7. A method as claimed in claim 6, wherein at least one network node is a concentrator or a communications gateway connected to a residential home area network (HAN) or local area network (LAN) to which there is connected at least one local electronic device, or wherein the network node is a local electronic device.
8. A method as claimed in claim 6 or 7, wherein confirming whether or not the data file was received at a particular network node comprises the steps of: operating a second base station to transmit an instruction to the network node in relation to the data file; and if the data file was not received at the network node, in response to receipt of the instruction at the network node, transmitting from the network node to the second base station data confirming that the data file was not received.

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9. A method as claimed in claim 8, wherein the instruction sent to the network node in relation to the data file is a software activation instruction.
10. A method as claimed in any of claims 6-9, wherein the local electronic device is a smart meter for monitoring local consumption of a utility service such as gas, water or electricity.
Ii. A method as claimed in claim 10, wherein the data file is software for a smart meter.
12. A method as claimed in claim 11, further comprising a central server capable of operating the first and second networks of first and second base stations to send and receive data files to smart meters associated with the network nodes.
13. A method as claimed in claim 12, wherein the server operates the first and second networks such that only software files are sent to smart meters using the first network, and such that all other data communication with the smart meters is performed using the second network.
14. A method as claimed in claim 12 or 13, wherein the data files include target addresses such that, after the central server operates the first and second networks to broadcast the data files to all smart meters in range, only the targeted smart meters having a specified address will use the data file.
15. A method as claimed in claim 12 or 13, wherein after the central server operates the first network to broadcast a data file, the central server operates the second network to broadcast addressed software activation instructions to all smart meters to activate the software provided by the data file only on targeted smart meters having addresses specified in the activation instructions.

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16. A method as claimed in claim 15, wherein when a smart meter receives an activation instruction for a data file it has not received, the network node associated with the smart meter transmits data to the relevant second base station confirming that the data file has not been received.
17. A method as claimed in any preceding claim, wherein the first network of first base stations is a network of Digital Audio Broadcasting (DABIDAB+/DMB) radio transmitters and the first communications channel is a Digital Audio Broadcasting communications channel.
18. A method as claimed in any preceding claim, wherein the second network of second base stations is a cellular network of Long Range Radio transceivers and the said second communications channel or channels is/are a digital radio communications channel or channels.
19. A communications system for wire lessly transmitting a data file to a network node, comprising: a first network of first base stations, each first base station having a wireless transmitter configured to transmit data over a first communications channel of the first network; a cellular second network of second base stations with a coverage area overlapping the coverage area of the first network of first base stations, each second base station having a wireless transceiver configured to transmit and receive data over a second communications channel or channels of the second network, the channel capacity of the or each second communications channel by which each second base station transmits data being less than the channel capacity of the first communications channel; and a plurality of network nodes dispersed throughout the first and second networks, each network node having wireless communication means capable of receiving data from a first base station over the first communications channel and capable of data communication with a second base station over a said second communications channel; -25 -wherein the first network of first base stations is configured to be operable to broadcast a data file to be received by the network nodes over the first communications channel; wherein each network node is configured to be able to confirm whether or not the data file was received at that network node by communication over a said second communications channel with the second base station of the relevant cell of the second network of second base stations; and wherein the second network of second base stations is configured to broadcast the data file over a said second communications channel in those cells where network node confirms that a data file is not received at that network node.
20. A communications system as claimed in claim 19, wherein the coverage of the cellular second network of second base stations extends to locations outside the coverage of the first network of first base stations.
21. A communications system as claimed in claim 19 or 20, wherein the coverage of the cellular second network of second base stations is greater than the coverage of the first network of first base stations.
22. A communications system as claimed in claim 19, 20 or 21, wherein the system is configured such that only those second base stations of cells of the cellular second network in which a network node has confirmed that the data file was not received broadcast the data file over a said second communications channel.
23. A communications system as claimed in any of claims 19-22, wherein the system is configured such that only those second base stations of cells of the cellular second network in which a network node has not confirmed that the data file was received broadcast the data file over a said second communications channel.
24. A communications system as claimed in any of claims 19-23, wherein the conununications system further comprises a local electronic device associated with a network node.
25. A communications system as claimed in claim 24, wherein at least one network node is a concentrator or a communications gateway connected to a residential home area network (HAN) or local area network (LAN) to which there is connected at least one local electronic device, or wherein the network node is a local electronic device.
26. A communications system as claimed in claims 24 or 25, wherein, to confirm whether or not the data file was received at a particular network node, the system is configured such that: a second base station is operable to transmit an instruction to the network node in relation to the data file; and if the data file was not received at the network node, in response to receipt of the instruction at the network node the network node transmits to the second base station data confirming that the data file was not received.
27. A con-imunications system as claimed in claim 26, wherein the instruction sent to the network node in relation to the data file is a software activation instruction.
28. A communications system as claimed in any of claims 24-27, wherein the local electronic device is a smart meter for monitoring local consumption of a utility service such as gas, water or electricity.
29. A communications system as claimed in claim 28, wherein the data file is software for a smart meter.
30. A communications system as claimed in claim 29, further comprising a central server configured such that it is capable of operating the first and second -27 -networks to send and receive data files to smart meters associated with the network nodes.
31. A communications system as claimed in claim 30, wherein the server is configured to operate the first and second networks such that only software files are sent to smart meters using the first network, and such that all other data communication with the smart meters is performed using the second network.
32. A communications system as claimed in claim 30 or 31, wherein the data files include target addresses and wherein the system is configured such that, after the central server operates the first and second networks to broadcast the data files to all smart meters in range, only the targeted smart meters having a specified address will use the data file.
33. A communications system as claimed in claim 30 or 31, wherein the central server is configured such that, after the central server operates the first network to broadcast a data file, the central server operates the second network to broadcast addressed software activation instructions to the smart meters, the smart meters being configured such that the software provided by the data file is activated only on targeted smart meters having addresses specified in the activation instructions.
34. A communications system as claimed in claim 33, wherein the system is configured such that, when a smart meter receives an activation instruction for a data file it has not received, the network node associated with the smart meter transmits data to the relevant second base station confirming that the data file has not been received.
35. A communications system as claimed in any preceding claim, wherein the first network of first base stations is a network of Digital Audio Broadcasting (DAB/DAB+/DMB) radio transmitters and the first communications channel is a Digital Audio Broadcasting communications channel.

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36. A communications system as claimed in any preceding claim, wherein the second network of second base stations is a cellular network of Long Range Radio transceivers and the second communications channel is a digital radio communications channel.
37. A smart meter for use in a smart metering communications system as claimed in any of claims 28-34, the smart meter being arranged to, in use, monitor local consumption of a utility resource, the smart meter having transceiver means arranged to: in use, receive data files transmitted via the first network of first base stations using the first communications chaimel; and in use, send and receive data communications via the cellular second network of second base stations using the second communications channel or channels; the smart meter further comprising data processing apparatus for operating the smart meter in accordance with the method claimed in any of claims 10-16.
38. A smart meter as claimed in claim 37, wherein the transceiver means comprises a transceiver arranged to, in use, conimunicate with a concentrator or a communications gateway via a residential home area network (HAN) or local area network (LAN) and to, in use, communicate with the first and second networks via the concentrator or the communications gateway, the concentrator or communications gateway thereby acting in use as a network node in the first and second networks.
39. A smart meter as claimed in claim 37, wherein the transceiver means comprises a receiver arranged to, in use, directly receive data files from the first network of first base stations over the first communications channel and a transceiver arranged to, in use, directly send and receive data communications from the cellular second network of second base stations over the second communications channel or channels, the smart meter thereby acting in use as a network node in the -29 -first and second networks.
40. A communications gateway for use in a smart metering communications system as claimed in claim 25, the communications gateway comprising: a receiver arranged to, in use, directly receive data files from the first network of first base stations of the communications system over the first communications channel; a transceiver arranged to, in use, directly send and receive data communications via the cellular second network of second base stations of the communications system over the second communications channel or channels; and a transceiver arranged to, in use, communicate with a smart meter via a residential home area network (HAN) or local area network (LAN); the communications gateway being arranged to, in use, act as a network node in the first and second networks and to, in use, relay data files and data communications between the smart meter and the first and second networks; the communications gateway further comprising data processing apparatus for operating the communications gateway in accordance with the method claimed in any of claims 7 and claims 8-16 when dependent on claim 7.
41. A concentrator for use in a smart metering communications system as claimed in claim 25, the concentrator comprising: a receiver arranged to, in use, directly receive data files from the first network of first base stations of the communications system over the first communications channel; a transceiver arranged to, in use, directly send and receive data communications via the cellular second network of second base stations of the communications system over the second communications channel or channels; and a transceiver arranged to, in use, communicate with a smart meter via a residential home area network (HAN) or local area network (LAN); -30 -the concentrator being arranged to, in use, act as a network node in the first and second networks and to, in use, relay data files and data communications between the smart meter and the first and second networks; the concentrator further comprising data processing apparatus for operating the concentrator in accordance with the method claimed in any of claims 7 and claims 8-16 when dependent on claim 7.
42. A central server for operating a smart metering communications system as claimed in claim 30, the server comprising interfacing means arranged to, in use, interface with the first and second networks to communicate with a remote smart meter, and data processing apparatus for operating the central in accordance with the method claimed in any of claims 10-16.
43. A computer software product which when run on a smart meter as claimed in claims 3 7-39 causes the smart meter to operate in accordance with the method claimed in any of claims 10-16.
44. A computer software product which when run on a communications gateway as claimed in claim 40 causes the communications gateway to operate in accordance with the method claimed in any of claims 7 and claims 8-16 when dependent on claim 7.
45. A computer software product which when run on a concentrator as claimed in claim 41 causes the concentrator to operate in accordance with the method claimed in any of claims 7 and claims 8-16 when dependent on claim 7.
46. A computer software product which when run on a server as claimed in claim 42 causes the server to operate in accordance with the method claimed in any of claims 10-16.
47. A communications system substantially as hereinbefore described, with reference to Figures 2 and 3. -31 -
48. A smart meter substantially as hereinbefore described, with reference to Figures 2 and 3.
49. A concentrator substantially as hereinbefore described, with reference to Figures 2 and 3.
50. A communications gateway substantially as hereinbefore described, with reference to Figures 2 and 3.
51. A central server substantially as hereinbefore described, with reference to Figures 2 and 3.
52. A method of operating a communications system to wirelessly transmit a data file to a network node, the method being substantially as hereinbefore described, with reference to Figures 2 and 3.