“Test Zone” Beeline: go into the pressurized gate, dress warmer in the machine room and turn off the phones


    Elements of the antenna system: RF cable, variable attenuator (test load)

    The object looks like a data center hall , only the equipment is more mixed and the engineers working with it are in the hall for a longer time. From 2 to 6 groups of engineers work constantly with equipment. Walking through the hall, you can catch the warmly dressed Huawei engineers, Europeans in the classic dress code, or Beeline experts who take tests and control everything that happens.


    Engineers turned around right in the machine room, but much more often the work goes remotely.

    Inside, up to 15 cellular networks of various standards and manufacturers work simultaneously. On an area of ​​250 square meters there are about a hundred racks in which full-fledged segments of the trunk transport network, urban transport network, billing, packet and voice backbone networks, controllers and base stations of mobile networks of various standards are implemented.

    Traffic Further many photos of equipment.

    When equipment manufacturers offer us their new solutions, before putting them into a live network, you need to make sure that the equipment works as we need, and conduct a wide variety of tests. As a rule, we are talking about “heavy” solutions of the Core Network level (each of which can consist of several racks), new base stations of different standards, equipment of the transport network, and so on. Of course, you need a place where all this can be assembled, turned on, configured and tested. There has been such a place in Beeline for many years - this is the “Test Zone” of the DTR.


    View from the height of a stepladder

    Based on the results of the tests performed, the optimal configuration of the hardware, the necessary software functions are selected, and all parameters are fine-tuned for perfect joint operation of all devices.

    Despite the high speed of equipment rotation (whole racks can change several times during the month), the requirements for installation quality remain the same as on commercial sites. Otherwise, you can lose several weeks on unsuccessful tests of advanced solutions, and the problem will be in a carelessly crimped cable. Yes, and the classic understanding that “only beautiful planes fly well” is absolutely true for our sphere - only beautifully laid cables work well!


    Proper installation of cables connected to a multiport switch

    The number of cabling laid in TK cannot be estimated; power supply cables alone lie under a raised floor for about 12 kilometers.

    The gateway at the entrance to the engineering wing serves for added security. The second gateway door will only open when the first one closes.



    Safety requirements for engineers working in the Test Zone are very high, and they relate to both safety itself and knowledge of labor protection and electrical safety. For example, a group of Chinese engineers configuring their equipment. To get the right of access to the premises of the TK, you need to have an access level of the 3rd group for electrical safety (for working with electrical installations with voltage up to 1000V), because foreign citizens will not be able to get Russian-style documents - they work here only accompanied by our experts who have the necessary permissions.


    A brainstorm performed by Chinese engineers.

    Before entering, it is better to turn off mobile phones, since behind this door, there is a real riot on the air.


    Armored door to the premises of TK

    In a confined space, more than a dozen base stations of different standards (GSM / UMTS / LTE / Wi-Fi) and different manufacturers can simultaneously work, how your phone will behave in such a complex radio environment is a big question. Often, those who did not take care of disconnecting the phone in advance will remain confident that they are in touch, while a phone driven crazy by the test radio has long been waiting for a reboot to return to its native mobile network.

    To reduce the level of radiation from base stations to safe ones - each base is equipped with attenuators (constant or variable) - devices to reduce the intensity of the electromagnetic signal.


    Elements of the antenna system: RF cable, permanent attenuator, omnidirectional antenna - OMNI

    At the same time, to conduct tests of a specific base station, it is necessary to ensure complete isolation from external factors, approximating the state next to the test telephone, close to the "spherical radio signal in vacuum." For this, special shielded cabinets are used - radio frequency anechoic chambers that do not pass EM signals. Of course, they don’t let it pass — it’s said a lot, or rather it will be - they don’t miss it much and the less it is “almost”, the more expensive the anechoic chamber. TK Beeline is equipped with several anechoic chambers, the shielding properties of which are sufficient for our tasks.


    Inner wall of an RF anechoic chamber

    An anechoic chamber with panel antennas and telephones inside for testing mobile networks. The door closes, power is supplied to the base station transceiver, and we can begin testing.


    Everything is ready for the beginning of tests of the mobile network.


    Panel antennas in an anechoic chamber and a test mobile phone.


    And here you can see the rack from which the tests go. Ericsson multistandard base station with RF cables, fixed and variable attenuators and anechoic chamber.

    How does it all work



    To ensure the smooth operation of TK, all conditions are created:
    - Redundant power for commercial equipment, power management rack:



    The color scheme may be unexpected, but, most importantly, the equipment functions:



    - Automatic fire extinguishing system:



    - Video surveillance system - cameras monitor each row of equipment :





    equipment in the room flows through the freight elevator, and directly in the premises of TK mounted platform for lifting equipment imported to the level of the raised floor:



    for rooms with falshp scrap, one of the main tools - suction cup, commonly called the "frog":



    This is how to lay cables under the raised floor, using special cable trays and trays:



    To connect the equipment in the “Test Zone” to the power supply network, it was decided to try out the offer from ABB, “Smissline Plug-in Electrical Installation System”.


    Automatic machines with installed current sensors, which can be used to monitor the load on each automatic machine in real time.


    Implementation of the Smissline system solution in the distribution panel (wall-mounted hanging version)


    Smissline bus system nearby, ease of installation, protection against electric shock, flexibility and time saving when replacing consumer machines

    What is iron




    Racks in even rows. Installation work is completed, all racks are closed.

    In the technical specifications, nodes of almost all systems and vendors operating in Beeline are functioning: CS Core equipment - MSC / VLR / MGW / HLR, PS Core - SGSN / GGSN / MME / ePC, GSM radio subsystem - BSC / TRC / BTS, UMTS - NodeB / RNC, LTE - eNodeB. In addition, segments of transport networks are emulated - MEN, IP / MPLS. Such a complete "set" of equipment allows you to collect schemes that are as close as possible to a commercial network, but devoid of influence on the services of "live" subscribers. If there is any question related to checking the existing equipment - before implementing the configuration in commercial networks, the necessary settings are applied on the test equipment, and we can assess their impact on all the nodes with which it interacts.

    Next - a small photo tour of some equipment that works in our TK.


    Huawei's multi-standard base station for indoor use

    One of the elements of an obsolete legacy is the cross-panel for cross-linking E1 streams. In the new equipment, this type of transport is practically not used, all networks are switched to optical transport (STM) or to Ethernet FE / GE / 10GE channels.


    Copper Cross (DDF 120 Om) with KRONE Skirtings. It is mainly used to provide GSM base stations with transport.


    A router that implements a test segment of the base stations transport network. Do not sign the cable here fatally


    Ericsson's GSM BSC controller model evoBSC8200 (the latest model from a Swedish manufacturer)


    Huawei Voice Switch MSoftx3000


    The Cisco ASR5000 chassis, on which the test Packet Core for GSM / UMTS / LTE network segments is built


    Telecom equipment of internal IP Backbone test Packet Core based on Cisco




    Huawei OSTA 2.0 test chassis cards. The chassis of Huawei OSTA 2.0, on which the test IMS Core is built.


    Racks with Comverse equipment, which implements a test segment of the billing system.




    Internal panels (optical and Ethernet) in a rack with Nokia MGW equipment.


    Compact base station of the ZTE standard.


    Radio transmitters (RRU) of various standards (2G / 3G / 4G) and various Manufacturers Ericsson Multi -


    Standard Indoor Base Station


    Ericsson GSM pico base station

    One of the most important tasks of the ToR is to test the functionality of new equipment. For example, with the advent of commercial LTE networks, in Russia there were enthusiastic and knowledgeable people who managed to establish the production of low-power base stations of the LTE standard (http://ranberry.net/en).

    Beeline, together with Russian developers, conducts full-featured testing of pico eNodeB LTE, checking all aspects - from the ease and reliability of integrating a base station into an existing mobile network, to checking mobility procedures between a new base and existing ones.


    The inscription “Made in Russia” is an extremely rare occurrence on such devices.


    Combined Wi-Fi + Femto 3G module manufactured by Cisco.

    Take a closer look at it, now the development of the direction of miniature multi-standard devices has been outlined in telecom, and perhaps very soon such solutions can be purchased for personal use in a regular electronics store. Now the tests are ongoing and are very successful.


    MetroEthernet test network segment - Alcatel-Lucent 7750 SR-7 router


    A transport network segment for connecting multi-standard base stations using Alcatel-Lucent and Cisco equipment.


    KVM module located in the Huawei rack.

    Such modules can often be seen in telecommunication racks, they are used to organize local access to equipment.


    Ericsson UMTS Transmitter


    Packet Traffic Balancer

    And finally, a couple of exhibits that you are unlikely to meet in ordinary data centers, or in the machine rooms of a telecom operator:

    First exhibit:



    It seems that it looks like an old radio that once stood by my grandmother, and even evokes “ warm-tube "associations.

    In fact, this is the latest UMTS radio controller - RNC, from NSN. In our TK, the first model of this type of equipment in Russia was installed, integrated and successfully passed tests.



    Second exhibit:
    It looks like a strange multiport server, also locked with a combination lock.



    This is one of the key elements for performing tests of the transport network - the Spirent Test Center, which allows you to create in packet networks almost anything you can think of to implement the most tricky test scenarios. In the current configuration, the test center has 8x10GE and 4xGE ports and allows you to generate various types of L2 / L3 traffic (both unicast and multicast / broadcast); emulate tens of thousands of client devices and routers with full support for all major network protocols, such as routing protocols (OSPF, BGP, IS-IS); basic service protocols (ARP, DHCP); MPLS synchronization (PTPv2, SyncE). This kit allows you to conduct a full set of functional and load tests of the equipment of the transport network.

    We were taken along the “Test Zone”:


    Polyak Evgeny Olegovich,
    the permanent leader of the “Test Zone” since its founding,


    Viktor Gennadievich Glebov,
    leading expert of the mobile core network development service

    References



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