EN 13757-5:2008

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.RGþLWDYDQMHKommunikationssysteme für Zähler und deren Fernablesung - Teil 5: WeitervermittlungSystèmes de communication et de télérelevé des compteurs - Partie 5 : Relais sans filCommunication systems for meters and remote reading of meters - Part 5: Wireless relaying35.100.20Podatkovni povezovalni slojData link layer35.100.10Physical layer33.200Daljinsko krmiljenje, daljinske meritve (telemetrija)Telecontrol. TelemeteringICS:Ta slovenski standard je istoveten z:EN 13757-5:2008SIST EN 13757-5:2008en01-december-2008SIST EN 13757-5:2008SLOVENSKI
STANDARD
EUROPEAN STANDARDNORME EUROPÉENNEEUROPÄISCHE NORMEN 13757-5October 2008ICS 33.200; 35.100.10; 35.100.20 English VersionCommunication systems for meters and remote reading ofmeters - Part 5: Wireless relayingSystèmes de communication et de télérelevé descompteurs - Partie 5 : Relais sans filKommunikationssysteme für Zähler und derenFernablesung - Teil 5: WeitervermittlungThis European Standard was approved by CEN on 16 August 2008.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the CEN Management Centre or to any CEN member.This European Standard exists in three official versions (English, French, German). A version in any other language made by translationunder the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as theofficial versions.CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMITÉ EUROPÉEN DE NORMALISATIONEUROPÄISCHES KOMITEE FÜR NORMUNGManagement Centre: rue de Stassart, 36
B-1050 Brussels© 2008 CENAll rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 13757-5:2008: ESIST EN 13757-5:2008

The main use of this standard is to support routed wireless networks for the readout of meters. NOTE Electricity meters are not covered by this standard, as the standardisation of remote readout of electricity meters is a task for IEC/CENELEC. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 13757-1:2002, Communication system for meters and remote reading of meters – Part 1: Data exchange EN 13757-3:2004, Communication systems for and remote reading of meters – Part 3: Dedicated application layer
EN 13757-4:2005, Communication systems for meters and remote reading of meters – Part 4: Wireless meter readout (Radio meter readout for operation in the 868 MHz to 870 MHz SRD band) EN 60870-5-1:1993, Telecontrol equipment and systems – Part 5: Transmission protocols – Section 1: Transmission frame formats (IEC 60870-5-1:1990) EN 60870-5-2:1993, Telecontrol equipment and systems – Part 5: Transmission protocols – Section 2: Link transmission procedures (IEC 60870-5-2:1992) EN 62054-21, Electricity metering (a.c.) – Tariff and load control – Part 21: Particular requirements for time switches (IEC 62054-21:2004) ETSI EN 300 220-1:2000, ElectroMagnetic Compatibility and Radio Spectrum Matters (ERM); Short Range Devices (SRD); Radio equipment to be used in the 25 MHz to 1 000 MHz frequency range with power levels ranging up to 500 mW; Part 1: Technical characteristics and test methods ETSI EN 300 220-2:2000, ElectroMagnetic Compatibility and Radio Spectrum Matters (ERM); Short Range Devices (SRD); Radio equipment to be used in the 25 MHz to 1 000 MHz frequency range with power levels ranging up to 500 mW; Part 2: Supplementary parameters not intended for conformity purposes ETSI EN 301 489-1:2008, Electromagnetic compatibility and Radio spectrum Matters (ERM); ElectroMagnetic Compatibility (EMC) standard for radio equipment and services; Part 1: Common technical requirements ETSI EN 301 489-3:2002, Electromagnetic compatibility and Radio spectrum Matters (ERM);ElectroMagnetic Compatibility (EMC) standard for radio equipment and services; Part 3: Specific conditions for Short-Range Devices (SRD) operating on frequencies between 9 kHz and 40 GHz RFC 1662 July 1994, HDLC-like Framing, Appendix C. Fast Frame Check Sequence (FCS) Implementation 3 Terms and definitions For the purpose of this European Standard, the following terms and definitions apply. SIST EN 13757-5:2008

Key A – G simple meters Z
data collecting unit/primary station Figure 1 — Network with simple nodes, without relaying Extending the network by adding some nodes with relaying capability will give a structure as shown in Figure 2. Nodes F and G have now been extended to include relaying capability. Communication between nodes A, B and D and the primary station is achieved by relaying the data through nodes G and F. Node A sends data to node G, node G relays data to node F and node F relays data to node Z, the data collecting unit. The size of the network can now be extended to include all of the nodes shown. Nodes F and G may be dedicated relaying nodes or meters with extended capabilities. Transmission from one node to another is called a hop. The transmission from node A to the data collecting unit/primary station consists of three hops. B A G E D F Z C SIST EN 13757-5:2008

Key A – E simple meters F, G
nodes with relaying capability Z
data collecting unit/primary station Figure 2 — Network with relaying nodes Note that the network still has a hierarchical structure at the application level, despite the relaying nodes. All end-to-end data transfer is performed between the data collecting unit and the meters. The meters do not communicate with one another at the application level, nor do the relays.
Key A
meter GW
node with relaying capability Z
data collecting unit/primary station Figure 3 — Router vs. gateway solution
The relaying can be performed in two different ways as shown in Figure 3, using either a gateway or a router approach.
ZAZ A Gateway approach Router approach APP NET LINK PHY GW B A G E D Z C F SIST EN 13757-5:2008

4.5.2 Data duplication Not all data sent upstream should be forwarded, as this may cause data duplication. This is can be seen in Figure 4 below.
Key A – E simple meters F, G
nodes with relaying capability Z
data collecting unit /primary station Figure 4 — Data duplication Data sent by node E can be received by gateway G as well as by gateway F. When node E sends a set of data, it will be received by both gateways. One set of data will be sent along the path E – G – F to node Z, the data collecting unit, and another set of data will be sent along the path E – F to node Z. The use of unconditional relaying will cause duplication of the data received by the data collecting unit and cause unnecessary traffic on the network as well. Methods and rules need to be implemented to ensure that data duplication is avoided.
Two issues should be handled when looking into avoidance of data duplication: a) whether to use enabling or disabling lists; b) whether to use a list of local or global nodes. The nature of radio communication is that the actual transmitting distance may vary a lot over time. It is thus not feasible to generate a list of nodes not allowed to relay for. Special transmitting conditions, due to for instance special metrological conditions, may make it possible to hear nodes located far away. It is as well B A G E D F Z C SIST EN 13757-5:2008

Key A receiver ‘listening’ window B wake-up and data signal C receiver active D data transmitted Figure 5 — Power strobed receiver The duration of the wake-up sequence shall be long enough so that it is detected by the node during the first listening interval to ensure an effective data transfer, i.e. it must be longer than the listening interval of the receiver. To prevent unnecessary wake-up of meters, the wake-up signal uses a different data rate than normal data transfers. On-going data transfers between nodes will not awake sleeping nodes, thus saving power.
The parameters specifying power wake-up behaviour should be standardised to ensure energy efficient data transfer in the radio network. 4.7 Error handling The data error rate will be higher in a radio based network than in a wired network. Some of the reasons for this are:  the units are operating in a license free band, where a lot of other units may be operating at the same time. Such units may garble or block the transmission between a pair of nodes in the metering network;  noise from other sources may impair the signals;  the radio transmission conditions may change due to changes in the environment (new building erected, container placed in front of the meters) or changes in weather conditions;  the transmission of information from a meter to the data collecting unit may traverse multiple links. The overall transmission is only successful if all of the individual hops, forth and back, are successful.
All this makes it necessary to use efficient error handling algorithms in a radio based relayed network. To alleviate the error handling, the following concepts are implemented in the protocols used:  data transmission is acknowledged for each hop;  there is a fast acknowledge at the link layer; A B C D 1
9 10
11 SIST EN 13757-5:2008
New regulations in the energy market [COM (2003) 739 Final] demand improved energy efficiency. This requires reporting of actual time of use and thereby precise time information from the meters. Standards for energy meters, like EN 62054-21, already quantify these requirements. This imposes capabilities of precision timing in the meters, and thereby for a communications system that allows for a precision time synchronisation through the network.
This need is to some extent in conflict with the use of power strobed meters and routers as shown in Figure 6 below.
Figure 6 — Time synchronization propagation
The scenario is that a network node A distributes a time synchronization signal to some other nodes in the network, nodes B and C. One of the receiving nodes B is asleep and will need a wake-up signal before data can be transferred to it.
The management application in node A retrieves the time information at tA. The information is processed by the lower protocol layers in the node, and sent to the network at tB. The information isn’t detected by the receiving node that is asleep. This will at tC cause a timeout condition in the sending node A, as no acknowledge signal is received. The time-out condition will cause the link layer in node A to send a ‘wake-up’ signal at tD, followed by a retransmission of the packet at tE. The receiving node, B, is now awake and will receive the data at tF, acknowledge the packet, and send the packet on to node C. Node C receives the data at tG and passes the information on to the application layer at tH. Time syncApp.LayerLink LayerSend dataWake upSend dataLink LayerAsleepAwakeRecv.dataNetwork node ANetwork node BTimeSend dataAcknow.Recv.dataNetwork node CLink LayerAcknow.App.LayerTime syncABECDGFHSIST EN 13757-5:2008

A transmission protocol must be devised, that ensures that precise timing information can be transferred. Such a protocol must take into account the delay introduced during the end-to-end transmission. This information shall be updated for each hop in the transmission. This processing of the data must be performed at the link layer of the nodes. Experience from other precision timing protocols like IEEE 1588-2002 shows that this requires a special handling at the lower protocol layers. A special set of lower layer protocols will be specified for this purpose. The protocol shall contain a synchronisation time tA as well as delay information tH - tBA. The synchronization time shall be a part of the application data. The delay information shall be a part of the link layer information. The delay information shall be updated for each hop/retransmission of the data. This protocol may be used if requirement for precision timing exists. NOTE Interconnection to meters using an EN 13757-4 interface can be achieved using an application layer gateway.
4.9 Protocol possibilities
Based on the general needs expressed in this clause, three different protocols for relaying in a radio network are defined. They have the following general characteristics:  A gateway based protocol: this protocol is intended for the extension of networks using the R2 mode as specified in EN 13757-4. Nodes using the gateway protocol may be meters as well as dedicated gateway nodes. They will interoperate seamlessly with R2 nodes. The gateway protocol can be used to extend the size of R2 networks. This is the protocol to use, if one wants to extend an existing network of R2 nodes. Networks using such gateways will anyway still have the constraint of a master/slave structure and a single address link layer.  A router based protocol: this protocol, named mode P, extends the addressing to a dual address /balanced protocol as used by all modern data link layer protocols. This is done using the EN 60870-5-1 physical layer and EN 60870-5-2 link layer. Nodes using the mode P protocol cannot communicate directly with R2 nodes but the nodes can coexists in the same frequency band. The P and the R2 protocols are by structure very similar and dual-mode nodes supporting mode R2 as well as mode P may be foreseen. This is the protocol to use when one wants to use a true routed network with full addressing, but at the same time wants to keep the general structure of the R2 protocol.  A contemporary protocol supporting precision timing: this protocol, named mode Q, is intended where one hasn't the need of following the EN 60870-5 series of standards. These EN 60870-5 series of standards were developed around 15 years ago and do not fulfil all the needs of a modern protocol. Mode Q takes into account the possibility of energy saving using power strobing of the nodes, the needs for transfer of precision timing information and the possibility of using NRZ coding based on digital signal processors. The protocol is applicable as the transport service for a modern object oriented high level application layer service like the DLMS protocol specified in EN 13757-1. SIST EN 13757-5:2008

Table 1 — Mode P, general Characteristic Min. Typ Max. Unit Frequency band a 868.0
868.6 MHz Channel spacing
kHz Transmitter duty cycle b
1 % NOTE The characteristics are, for the SRD band, identical to the characteristics for the S and R2 modes in EN 13757-4. a
The standard is optimised for the 868 - 870 MHz band, but with local radio approval it may allow for operation in other frequency bands. b
Duty cycle shall be as defined by ETSI EN 300 220-1 in the SRD bands. It may with local radio approval allow for other duty cycles in other frequency bands.
(other)
868.330
MHz
Centre frequency a
(meter)
868.030 +
n × 0.06 h
MHz
Frequency tolerance (meter / other)
0 ± 17 kHz ~ 20
...