GB2526091A

GB2526091A - Monitoring hub

Info

Publication number: GB2526091A
Application number: GB1408400.8A
Authority: GB
Inventors: Michael Simon Maddison; Bryn Anthony Smith
Original assignee: SENCEIVE Ltd
Current assignee: SENCEIVE Ltd
Priority date: 2014-05-12
Filing date: 2014-05-12
Publication date: 2015-11-18
Also published as: GB201408400D0

Abstract

A monitoring hub 100 is provided for use in a sensor infrastructure of a station for an underground rail network. The monitoring hub includes: a wired or wireless interface to a first local area network 201 for the station, said first area local network providing external internet connectivity 205; a switch or other network facility to maintain a second local area network; a Wi-Fi (RTM) interface 241, 231 for providing sensing devices 210 wireless access to said second local area network; a local area network (LAN) interface 262 and power unit for providing sensing devices 260 with power and wired access to said second local area network; a low power wireless interface for performing data communications with sensing devices 210 using lower power than said Wi-Fi interface; and a data processing facility for retrieving data from said sensing devices. The monitoring hub may be further in communication with access points 270 daisy-chained down the tunnel to extend the range of the sensor network. The low power interface may be a FlatMesh 802.15.4 interface. Gateway node functionality may be incorporated into the monitoring hub. The monitoring hub may also obtain data from other sources in the underground station such as on-train telemetry data 241 or escalator SmartStep monitoring data 231.

Description

Intellectual Property Office Application No. GB1408400.8 RTIVI Date:21 October 2014 The following terms are registered trade marks and should be read as such wherever they occur in this document: Wi-Fi SmartStep Linux VirtualBox Oracle Microsoft Parallels TrainTracer Aistom Intellectual Property Office is an operating name of the Patent Office www.ipo.govuk

SENSOR INFRASTRUCTURE AND MONITORING HUB FOR AN UNDERGROUND RAIL

NETWORK

Field of the Invention

The present invention relates to a sensor or monitoring infrastructure and a corresponding monitoring hub for use in an underground rail network to support the monitoring of many diverse aspects of the rail network.

Background of the Invention

An underground rail network (metro or subway) is a highly complicated system, and a wide range of monitoring is performed in order to ensure and maintain correct operations of the overall system. For example, various aspects to be monitored include environmental and structural sensors within a tunnel, diagnostic information from trains, cameras and videos (e.g. for safety and security applications), escalators, and so on. The operator of an underground rail network may contract out the maintenance, monitoring and/or control of various such systems to different third parties, who in some cases will have installed the system being monitored and/or the monitoring equipment itself This often leads to a heterogeneous environment, in which operators of various monitoring equipment install their own infrastructure in order to provide power and/or communications to their own monitoring equipment. However, this duplication of infrastructure across equipment operators may cause problems in an underground rail network, which is usually subject to significant constraints in terms of the physical space available. Moreover, the heterogeneity of the different sets of monitoring data makes it harder for the operator of the underground rail network to maintain a clear and consistent overview of the current status of the network. For example, certain monitoring data may not be available in a timely fashion to the operator of the underground rail network from a third party monitoring system, and even if such data is available, it may be relatively difficult for the operator of the underground rail network to process, interpret and/or exploit such third party monitoring data.

Summary of the Invention

The invention is defined in the appended claims.

Brief Description of the Drawings

Various embodiments of the invention will now be described in detail by way of example only with reference to the following drawings: Figure 1 is a schematic diagram of a sensor infrastructure for an underground rail network in accordance with some embodiments of the invention.

Figure 2 is a schematic diagram of a monitoring hub from the sensor infrastructure for an underground rail network of Figure 1 in accordance with some embodiments of the invention.

Detailed Description

Figure 1 is a schematic diagram of a sensor infrastructure 10 for an underground rail network in accordance with some embodiments of the invention. Some components of the sensor infrastructure are generally located down one or more tunnels of the underground network. It will be appreciated that such tunnels provide a very challenging operating environment. Thus the amount of space in the tunnels is extremely limited, with only a small amount of clearance to allow the passage of trains through the tunnels. Furthermore, the tunnels may be in use for underground rail traffic for up to 365 days per year, from early in the morning until late at night. During these hours, it is therefore generally not feasible (or safe) for a workforce to operate inside the tunnels (without severe disruption of the rail traffic). Accordingly, the sensor infrastructure described herein seeks to provide a minimal footprint in terms of space requirements, especially with respect to installation along a tunnel, while at the same time recognising that the availability of certain facilities, such as power or communication links, may be restricted within a tunnel. In addition, the sensor infrastructure described herein seeks to support standalone operation with minimal maintenance requirements, thereby providing compatibility with the operational needs of a busy underground rail network.

The sensor infrastructure 10 of Figure 1 includes a monitoring hub 100 which provides connectivity to a wide range of sensor devices and other systems. The monitoring hub 100 is generally installed at a station in the underground rail network; typically each station is provided with its own monitoring hub 100. In other implementations, the monitoring hub may also be installed at least partway down a tunnel of the underground rail network.

Figure 2 is a schematic diagram of the monitoring hub 100 in accordance with some embodiments of the invention. The monitoring hub 100 may be implemented, for example, using an "industrial pc oras a special-purpose embedded system. The monitoring hub 100 includes various communications or network facilities, such as a WiFi (IEEE 802.11 b/gIn eto) interface 120 and a wired Ethernet interface 125, which supports communications over copper cabling and/or optical fibre, etc. Both the WiFi (IEEE 802.11) interface 120 and the wired Ethernet interface 125 therefore provide local area network (LAN) connectivity. In some embodiments, the WiFi interface 120 is implemented using an AWSSOO device from Atop (see www.atoo.com.tw), however, it will be appreciated that there are many other WiFi interface devices which are commercially available and could be used instead of (or as well as) an Atop AW5500. In some implementations, the WiFi interface 120 may be configured as a bridge if a station WiFi network is available, or as a WifFi access point if this is not available.

In some embodiments, the monitoring hub further provides a low-power wireless interface 115. Note that low-power in this context implies that the overall power requirement for a client device of wireless interface 115 is significantly lower than the corresponding power requirement for a client device of WiFi interface 120. Such power savings can arise from, for example, simpler communications protocols, which therefore require less processing (and hence less power consumption) at the client device, lower transmission strengths or data rates, etc. In some embodiments, the low-power wireless interface 115 is implemented using a FlatMesh network from Senceive Ltd (see wwwsencewecom). Such a network performs radio communications using the IEEE 802.15.4, 2.4 GHz ISM (industrial, science and medical) band.

The monitoring hub further includes a power unit 130 for receiving a power input 134, such as a 11 OV AC supply derived from the mains, and also providing a power output in one or more formats, such as 11 OV AC and/or low voltage DC. The monitoring hub 100 may also be provided with a local battery backup unit 135 to allow continued operations of the monitoring hub (or at least a controlled shut-down) in the event of a power interruption or failure. The battery backup unit 135 is usually on trickle charge during normal operations of the monitoring hub 100 under mains power.

The monitoring hub further includes a data processing system 150 and a data storage system 155. The data processing system may be provided, for example, on a printed circuit board (PCB) running a suitable embedded operating system such as Linux. The data processing system may run multiple system virtual machines on top of the operating system, such as VMware virtual machines, Virtual Box (from Oracle), Virtual PC (from Microsoft), Parallels (see www.parallels,com), etc, each system virtual machine providing a secure and segregated application execution environment (or alternatively each virtual machine may include its own operating system running on top of a hypervisor). This architecture allows the data processing system 150 to provide protected multi-user access, thereby supporting multiple applications from different vendors in a secure and confidential manner. The data storage system 155 may comprise solid state (flash) memory and/or disk storage as appropriate for access by the applications running on the data processing system 150.

Returning to Figure 1, the monitoring hub 100 is connected to one or more wireless sensor networks 210, each of which may be located along an underground tunnel, by low power wireless interface 115 and a low power wireless link 209. In some embodiments, the wireless sensor network(s) 210 is/are based on a FlatMesh network from Senceive Ltd (see www.senceve.corn). The FlatMesh network comprises multiple sensor nodes that can be positioned as desired in an environment to be monitored. The sensor nodes also function together as a network to allow the monitoring hub 100 to communicate with any given sensor node in the network via a gateway node (which may be incorporated into the monitoring hub 100), and then zero, one or more intermediate sensor nodes, depending upon the particular network configuration. The sensor nodes can communicate with one another over distances of tens of meters (although they are frequently placed closer together), and have a burst data rate of 250 kbit per second, with a typical duty cycle of 1%. (It will be appreciated that this is much lower than the data rate of a WiFi network, hence the much lower power requirements). The sensor nodes may be attached robustly to the underground tunnels by any suitable mechanism, including direct fixing (screws, bolts etc) and/or a magnetic bracket. The sensor nodes of the wireless sensor network 210 can be used for monitoring (data logging) a wide range of physical and environmental conditions, such as temperature, stress/strain, movement, vibration, etc. As mentioned above, it is desirable to minimise the level of maintenance work required down a tunnel. In view of this requirement, each sensor node may be provided with a lithium battery (or other suitable battery or cell) to give a typical operational lifetime of 1-5 years before needing a battery replacement. In addition, the network configuration is flexible, so that if any given sensor node fails, communications involving the remaining sensor nodes can be routed so as to bypass the failed node.

The monitoring hub 100 may be connected to two or more LANs. One such LAN is provided by the underground/metro railway station infrastructure itself, as part of the general computer installations and connectivity in the station. The monitoring hub 100 may access this station LAN 201 using a wired or wireless interface as appropriate. The choice of which type of connection to use may depend upon the location of the monitoring hub 100 within the station or tunnel. For example, if the monitoring hub 100 is located close to existing wired cabling for the station LAN 201, then it may be most convenient for the monitoring hub 100 to exploit this existing cabling in order to have a wired connection to the station LAN. In many cases however, any existing cabling of the station LAN 201 may be remote or just difficult to access from the monitoring hub 100. In such a situation, the monitoring hub 100 uses a wireless (WiFi) connection, as shown in Figure 1, for connection to the station LAN 201 via a suitable wireless access point (AP). On the other hand, if the monitoring hub is located some distance along a tunnel (rather than within a station), this might be out of range of a station WiFi network, in which case a wired connection to the station LAN 201 could be used. Note that in terms of the station LAN 201, the monitoring hub 100 acts as a device (client or node) which accesses the station LAN 201. For example, the AWSSOO device discussed above in connection with the WIFi interface 120 can be configured as a client of a wireless access point for station LAN 201.

The station LAN will usually provide a gateway (e.g. a router or other such device) for external connectivity, i.e. external to the station containing the monitoring hub 100. This external connectivity may be used to link, for example, to the Internet, and/or to an intranet for the operator of the underground rail network, and/or to an intranet of the operator of the monitoring hub 100 and/or other sensor equipment installed in the station and linked to the monitoring hub 100. In some implementations, the connectivity to the intranet(s) may be provided over a dedicated (private) network link, while in other implementations the connectivity to one or more of the intranet(s) may be provided over the Internet. A virtual private network (VPN) 205 may be formed over the Internet (or other network facility) to enhance the security of these connections. In particular, each client (equipment operator or user) can be provided with secure VPN access via station LAN 201 to the monitoring hub 100.

The external connectivity via station LAN 201 generally supports bi-directional communications between a system user and the data processing system 150 of the monitoring hub.

In one direction, the connectivity allows users to access and extract monitoring data, etc., from their sensor equipment which has been recorded or saved into data storage unit 155. In the opposite direction, the connectivity allows user to send messages such as operating commands, configuration instructions, etc to the various sensor devices via the monitoring hub 100. The monitoring hub therefore provides a form of remote access to the sensor devices, thereby avoiding the need for users to physically access the sensor devices themselves in order to retrieve data or provide suitable control messages (and to install separate communications links for each such device).

A rail network operator database 202 may also be connected to the station network 201. This database may be used to log data from some or all of the various sensor devices. Note that the operators or users of such sensor devices are frequently contractors operating in the underground rail system, for example, to provide maintenance services. Such contractors can generally access and control these sensor devices such as by using VFN 205 as described above. Nevertheless, it is also desirable from the perspective of the underground rail network operator to maintain in database 202 its own consolidated records comprising the set of data outputs from the various sensor devices (potentially belonging to one or more different contractors). For example, aggregating the data records together at database 202 allows the rail network operator to perform analyses of the overall set of data logged by all the different sensor devices (whereas a contractor will typically just be interested in looking at the data from its own particular sensor device(s)). The provision of useful data to the rail network operator is facilitated by defining a common (standard) data format within the monitoring hub for acquiring data from many different devices. This standard format is then available not only to the external users to access their own data, but also to the rail network operator to access the full set of data from the various devices.

The monitoring hub 100 further provides its own local area network (Ethernet or similar), for example by incorporating an Ethernet switch (not shown in Figure 2). In general, this hub-based LAN is separate (distinct) from the station LAN 201. In some implementations a bridge or other connectivity device may be used to link the two LANS, thereby allowing end-to-end connectivity between (for example) the extemal users over VPN 205 and the data logging devices attached to wireless sensor network 210. In other cases, the only linkage between the two LANs is that the data processing system 150 of the monitoring hub may communicate over both networks. Thus the data processing system 150 may, for example, receive data from various data logging devices attached to wireless sensor network 210 and then forward this data (or at least, make it available for external access) over station LAN 201. The data processing system 150 may store such received data temporarily in data storage unit 155 prior to forwarding to or downloading by an external user.

The hub-based LAN provides a wired interface 125 and also a wireless (WiFi) interface 120 as shown in Figure 1. As noted above, in some embodiments, the WIFi interface 120 is implemented using an AWS500 device from Atop, which can act as a WiFi access point (AP), as well as a conventional WiFi client. If the monitoring hub is to act simultaneously as both a WiFi access point and a conventional WiFi client, this can be achieved by having a pair of such devices coupled together in a bridge mode.

The WiFi interface 120, acting as a WiFi access point, can be used to support communications with a range of external devices. Various examples of such communications are illustrated in Figure 1, which shows the monitoring hub in communication with one or more station escalators 230, a data telemetry unit for a train which is temporarily located in the station, and a monitoring laptop 250 (over wireless links 231, 241 and 251 respectively). The escalator may be a "smart step" escalator (as described, for example, in http:./iwwwcornputerw 9. tr::w.i. This system involves multiple sensors and data logging equipment fitted within a step on the escalator to investigate operational wear patterns etc. by recording data at up to 100 times per second, and then downloading the data to a laptop computer on a daily basis. In the sensor infrastructure 10 shown in Figure 1, the recorded data is retrieved from the escalator smart step 230 using the WiFi interface 120 of the monitoring hub 100.

The WiFi interface 120 of the monitoring hub 100 is also used to exchange data with a train as it passes through (or stops in) the station of monitoring hub 100 (or passes the monitoring hub in a tunnel). Such wireless telemetry systems are implemented on existing trains, see for example, the Traintracer system from Alstom, h (, which uses wireless communications to report possible faults to maintenance crews, so that they can be forewarned of any potential repairs or maintenance tasks that might be required when the train arrives at an appropriate destination. It will be appreciated that systems such as "smart step" and Traintracer have traditionally used dedicated and bespoke communications facilities. However, the sensor infrastructure 10 of Figure 1 provides a single, integrated communications approach that reduces installation requirements in the relatively limited space of an underground rail network, and can also help to provide the operator of the underground rail network with a comprehensive overview of the status of various components of the network system.

As shown in Figure 1, the WiFi interface 120 of the monitoring hub 100 may also be used to interact with laptop 250 over link 251. This laptop may be used, for example, to retrieve data held by the monitoring hub within data storage unit 155, and/or to control the operations of the monitoring hub, such as by updating and/or configuring programs running on the data processing system 150. In addition, the laptop 250 may also utilise the WiFi interface 120 to communicate directly with other devices which are attached to the hub LAN (such as described below), again to retrieve data from such devices and/or to send control or configuration commands to such devices.

The monitoring also provides an external power output 261 from power unit 130 for supply to various other devices 260, such as data loggers, sensors, cameras and video, etc. In general, these power lines are accompanied by a data line to the wired interface 125 of the hub LAN, for example, as provided by one or more optical fibres 262 routed as appropriate (or any other suitable form of wired connection). The use of optical fibres 262 is attractive since they are robust, high capacity, and do not cause any electromagnetic compatibility (EMC) issues. The devices 260 can therefore obtain power and/or data connectivity as appropriate from this combination of power and data lines 261, 262.

The data lines 262 and Ethernet interface 125 allow the monitoring hub 100 to retrieve data held by such devices 260, and/or to control the operations of these devices, such by sending control commands, configuration instructions, software updates, etc to the devices over data lines 262.

One particular type of device that can be connected to the power unit 130 and Ethernet interface 125 of the monitoring hub 100 is a remote access monitoring point 270, which is used in effect to extend the reach of the monitoring hub 100 along a tunnel. Thus remote access monitoring point 270 receives power and data connectivity by connection(s) 269, for example, a 11 OV AC power supply and an optical fibre Ethernet cable. The remote access monitoring point 270 contains its own low power wireless interface, analogous to wireless interface 115 in monitoring hub 100, its own wired Ethernet interface, analogous to Ethernet interface 125 in monitoring hub 100, and its own power unit, analogous to power unit 130 in monitoring hub 100. The remote access monitoring point 270 is further provided with some form of control processor, with more extensive data processing typically being off-loaded onto the monitoring hub 100. The remote access monitoring point 270 may also provide a WIFi interface (not shown in Figure 1), analogous to W-Fi interface 120 in monitoring hub 100. This WiFi interface acts as an access point for use, for example, by client laptops in the tunnel, thereby providing them with connectivity through the remote access monitoring point 270 back to the monitoring hub 100.

The remote access monitoring point 270 provides power and/or data connectivity support to sensor devices, etc. located in the vicinity of the remote access monitoring point 270. For example, the remote access monitoring point 270 may support a low power wireless link 279 to low power wireless sensor networks 210A (analogous to wireless sensor networks 210 as described above), and provide a power line 271 and Ethernet connectivity 272 to devices 260A, such as cameras and data loggers (analogous to devices 260 as described above). In some cases, there may be multiple remote access monitoring points 270 which are linked together, for example, in a chain extending along a tunnel. The remote access monitoring points 270 may be located at regular intervals along the tunnel and/or at particular positions in the tunnel for which monitoring is specifically required.

Power and data connectivity are then passed along the chain from the monitoring hub 100, i.e. daisy-chained along the sequence of remote monitoring access points.

The provision of one or more remote access monitoring points 270 reduces the length of power and data cabling that is required to support a set of monitoring devices, since it is no longer necessary to provide such cabling for each device all the way back to the monitoring hub 100.

Rather, just a single set of cabling (power and data) is provided to the set of one or more remote access monitoring points 270, and devices 260A then only have to be linked to the nearest remote access monitoring point (rather than directly to the monitoring hub 100 itselt). This single set of cabling is quicker and cheaper to install, as well as easier to maintain. In addition, it also occupies less space within an underground rail tunnel. The provision of one or more remote access monitoring points 270 along the tunnel also helps to make future device installations easier and quicker, since they only have to be linked to the nearest remote access monitoring points 270, rather than individually wired back along a tunnel to the nearest station.

It will be appreciated that although Figures 1 and 2 illustrate an implementation of the sensor infrastructure 10 and monitoring hub 100 in accordance with some embodiments of the invention, each individual implementation will vary according to the particular circumstances of the given implementation. For example, in some stations, there may not be a station local area network 201. In these circumstances, there may be no facility for external users to directly access the monitoring hub 100. Alternatively, such access might be provided by other mechanisms, for example, a wired network connection which may be available in a station, or by using laptop 250, or by linking (potentially via one or more remote access monitoring points 270) a monitoring hub in one station via an optical fibre data connection 269 with a monitoring hub in an adjacent station that does have (access to) a station local area network. A further possibility is that a remote access monitoring point 270 may be positioned at a location where a cellular connection is available -e.g. to provide a GPRS or 3G connection (such connectivity is not normally available in the underground, but may exist in some situations, for example, near where the line starts to go overground. In addition, the set of devices, such as sensor devices 210, 21 OA, 260, 260A, escalator 230 and train 240, which link to a monitoring hub (directly or via one or more remote access monitoring points 270) will vary according to any particular installation. Furthermore, the supported types of data communication link, such as low power wireless 209, 279, hub Wi-Fl 231, 241, 251 and (wired) Ethernet links 262, 272, 269, many vary for any given monitoring hub and/or remote access monitoring point 270. In addition, the type of data connectivity adopted for any given device may depend on the circumstances of the relevant implementation and the particular device in question. For example, some or all of devices 260 might connect to the monitoring hub 100 via a Wi-Fi link rather than by optical fibre 262, although such devices may still have a wired power connection 261 from the monitoring hub 100 (alternatively, such devices may have independent power access, i.e. not through monitoring hub 100). Accordingly, it will be appreciated that the identity, model, functionality, configuration and connectivity of the devices and systems described with reference to Figures 1 and 2 can be modified to support the details of any particular implementation.

The approach described herein includes a monitoring base or hub 100 which can be installed on a permanent basis, and therefore re-used across multiple projects. Accordingly, the approach avoids having to keep re-installing hard-wired solutions from multiple different monitoring companies and thus is future-proofed. In addition, the approach is scalable and flexible, especially in conjunction with the use of one or more remote access monitoring points. Furthermore, the co-ordinated provision or power and data cabling avoids a "spaghetti" configuration of wiring, and also helps to reduce significantly overall wiring requirements, thereby offering cost and environmental benefits. As described above, each user can be provided with a secure link to access his/her own data over the station LAN, while at the same time the operator of the underground rail network can be provided with centralised access to all appropriate data streams for their own monitoring purposes in accordance with a standardized data format.

In summary, various embodiments described herein provide a monitoring hub for use in a sensor infrastructure of a station and/or tunnel for an underground rail network. The monitoring hub includes: a wired or wireless interface for connecting as a node of a first local area network for the station, said first local area network providing external connectivity to allow the monitoring hub to connect to the Internet; a switch or other network facility to maintain a second local area network; a WiFi interface for providing sensing devices wireless access to said second local area network; a local area network (LAN) interface and power unit for providing sensing devices with power and wired access to said second local area network; a low power wireless interface for performing data communications with sensing devices using lower power than said WiFi interface; and a data processing facility for retrieving data from said sensing devices.

In some implementations, one or more of the above components may be omitted, depending upon the particular circumstances and parameters affecting any given implementation. For example, in some cases a monitoring hub may provide sensing support and connectivity via a low power wireless interface or by using the second local area network, but not both (hence the low power wireless interface of the second local area network may be omitted if not required). Similarly, in some cases the monitoring hub may provide wired connectively to the second local area network or wireless connectivity to the second local area network, but not both. Furthermore, in some cases the monitoring hub may act as a bridge between the first and second local area networks (so they could potentially act together as if a single local area network). Other such variations and modifications that are appropriate to particular circumstances will be apparent to the skilled person.

In conclusion, various embodiments of the invention have been described. The skilled person will appreciate that these embodiments are provided only by way of example, and different features from different embodiments can be combined as appropriate. Accordingly, the scope of the presently claimed invention is to be defined by the appended claims and their equivalents.

Claims

Claims 1. A monitoring hub for use in a sensor infrastructure of an underground rail network, wherein said monitoring hub includes: a wired or wireless interface for connecting as a node of a first local area network for a station of the underground network, said first local area network providing external connectivity to allow the monitoring hub to connect to the Internet; a switch or other network facility to maintain a second local area network; a WiFi interlace for providing sensing devices wireless access to said second local area network; a local area network (LAN) interface and power unit for providing sensing devices with power and wired access to said second local area network; a low power wireless interface for performing data communications with sensing devices using lower powerthan said WiFi interface; and a data processing facility for retrieving data from said sensing devices.
2. The monitoring hub of claim 1, wherein said data processing facility is further configured to provide control instructions to the sensing devices.
3. The monitoring hub of claim 1 or 2, wherein said data processing facility is further configured to provide access for extemal users to the retrieved data over said first area local network providing external connectivity.
4. A sensor infrastructure for an underground rail network, said sensor infrastructure including the monitoring hub of any preceding claim.
5. The sensor infrastructure of claim 4, further comprising one or more remote access monitoring points to provide local infrastructure support to sensing devices which are located down a rail tunnel from the monitoring hub, wherein the one or more remote access monitoring points receive power and connectivity to the second local area network either directly from the monitoring hub, or indirectly via one or more intermediate remote access monitoring points.
6. The sensor infrastructure of claimS, wherein each remote access monitoring point includes: a local area network (LAN) interface and power unit for providing sensing devices with power and wired access to said second local area network; a low power wireless interface for performing data communications with sensing devices using lower power than said WiFi interface.
7. The sensor infrastructure of any of claims 4 to 6, wherein the monitoring hub is configured to receive sensing data from an escalator.
8. The sensor infrastructure of any of claims 4 to 7, wherein the monitoring hub is configured to receive sensing data from a train which is passing or has stopped nearby.
9. The sensor infrastructure of any of claims 4 to 8, wherein the monitoring hub is configured to transmit data from different sensing devices over said first area local network to a database for access by an operator of the underground rail network.
10. A method of operating a monitoring hub as claimed in any of claims I to 4 for use in a sensor infrastructure of an underground rail network, wherein method includes the monitoring hub performing the operations of: connecting the monitoring hub as a node of a first local area network for a station of the underground rail network, said first local area network providing external connectivity to allow the monitoring hub to connect to the Internet; maintaining a second local area network; providing sensing devices wireless access to said second local area network via a WIFi interface; providing sensing devices with power and wired access to said second local area network via a local area network (LAN) interface and power unit respectively; performed for performing data communications with sensing devices using a low power wireless interface requiring lower powerthan said WiFi interface; and retrieving data from said sensing devices into the monitoring hub.
11. The method of claim 10, further comprising providing control instructions from the monitoring hub to the sensing devices.
12. The method of claim 10 or 11, further comprising the monitoring hub providing access for external users to the retrieved data over said first area local network.
13. A method of operating a sensor infrastructure of an underground rail network, said method including operating the monitoring hub according to any of claims 10 to 12, and further comprising providing local infrastructure support to sensing devices by using comprising one or more remote access monitoring points which are located down a rail tunnel from the monitoring hub, wherein the one or more remote access monitoring points receive power and connectivity to the second local area network either directly from the monitoring hub, or indirectly via one or more intermediate remote access monitoring points.
14. A monitoring hub substantially as described herein with reference to the accompanying drawings.
15. A sensor infrastructure substantially as described herein with reference to the accompanying drawings.
16. A method of operating a monitoring hub substantially as described herein with reference to the accompanying drawings.
17. A method of operating a sensor infrastructure substantially as described herein with reference to the accompanying drawings.