What is DTMF What are the next steps? and why is it so important?  Planning and systematic transition to modern IP technologies DTMF technology enables control signals (e.g., number pad keystrokes, device identification or Because this concerns major changes, the other numerical codes) to be sent over a voice forthcoming modifications to emergency channel. Elevator communication devices use communication must be considered more DTMF to indicate identification numberand systematically. Elevator companies can use various conditions, for example, a flat battery. an advanced and secure platform that will give them a complete overview of the status Incorrect DTMF transfer means communication of serviced devices, prevent various error errors and undesirable behaviour of the entire The transition to conditions and reduce the time needed for emergency communications system. installation and servicing. technology is already taking  Replacement of incompatible devices – sufficiently in advance shape. Are you Replacing incompatible devices with a new ready for it? LTE gateway in the forthcoming years will be essential. This replacement will involve costs to acquire the devices as well as costs for configuration and installation by administrators and technicians. Replacing devices at the Many essential systems and devices used last moment should be avoided so that the in elevator technology today use mobile new LTE gateways can be implemented in the networks for connectivity. Some of the simplest and quickest way possible. biggest mobile carriers have already revealed their plans and timeframe for complete transition to the newer 4G technology.  Modernisation of dispatch centres This will be a major technological change, Existing dispatch centres at elevator companies and elevator companies should be seriously are usually built on a traditional PBX connected thinking about adopting suitable measures. to land lines (ISDN). The core networks of operators providing landlines today are built completely on IP technologies. Any conversions between VoIP (operator) and non-VoIP (customer) technologies pose a significant risk of distortion during DTMF transfer. The ideal option is to build a communications solution for elevator dispatch centres based purely on VoIP technologies.

2N TELEKOMUNIKACE a.s., Modřanská 621, 143 01 Praha 4, ČR, +420 261 301 500, [email protected], www.2n.cz How does it affect What is the solution? SIP over LTE 2 elevator technology? For emergency elevator communication, we In this scenario, the LTE network is used are mainly interested in voice transfer, which as data transfer technology through Elevators equipped with emergency LTE (data only) is not ideal for. The options which voice is transferred using a SIP communication systems make use of below are potential solutions. protocol. A SIP client registered centrally specialised equipment (gateways) to to a VoIP provider is implemented in the connect analogue communications devices LTE gateway. located inside elevator cabins to the digital mobile network. The mobile network then 1 transfers calls from the elevator cabin VoLTE through the land voice network to the VoLTE (Voice over LTE) is a technology  ADVANTAGES elevator company’s dispatch centre. enabling voice transfer directly over LTE  deals with . This is a solution that mobile networks DTMF transfer  DISADVANTAGES The majority of gateways used on the operators will use to replace voice services market today operate on either issues from older 2G and networks.  the need to prepare (GSM) or 3G (UMTS) networks. When  a range of VoIP elevator dispatch operators cease operating these networks, operators with centres (transition to elevator communications devices will affordable tariffs VoIP technologies) lose their connections to dispatch  DISADVANTAGES is available on the  centres and thereby compromise the  ADVANTAGES market the first devices will safety of passengers who may be stuck  modern codecs start appearing on the in an elevator unable to call for help.  the first VoLTE used in VoLTE do not  compatibility market in 2020 This may also have legal consequences, gateways are deal with the issue of with modern VoIP because a non-functional communications already available DTMF transfer, which switchboards device logically is unable to meet the is a crucial problem in  requirements of EN 81-28 standard. elevator signalisation the level of protocols (P100, CPC). development and coverage of LTE In many situations, gateways are also used  each operator to provide data connections between implements this other devices (e.g., lift controllers) and the 4G technology differently, Mobile elevator company’s monitoring systems. no as of now Terminating 2G and 3G networks will result network  VOiP carrier/PBX (phone in a loss of data transfer just as much as voice sound quality number for EasyGate connections for voice communications. is guaranteed only LTE under the terms of data the VoLTE network. However, elevator SIM dispatch centres VoLTE EasyGate 4G are also connected LTE Mobile possible DTMF to other networks, network SIM Media corruption Media and the essential EasyGate gateway gateway convertors cause VoLTE specific degradation of sound quality, LIFT Answering particularly problems 1 service VoIP in DTMF transfer. VoIP carrier/PBX (phone number for Answering service (any network LIFT answering service) 1 or technology)