IDM DXC5200 Time-Slot Cross-Connect Equipment

IDM DXC5200 240-group E1 time-slot cross-connect equipment is a time-slot cross-connect device developed by Beijing Ruiguang Jiyuan Digital Technology Co., Ltd. (Raytrans) using dedicated large-scale integrated circuits. As a professional PCM equipment, it performs 64K time-slot non-blocking cross-connection between 2.048Mbps E1 channels, and connects subscriber terminals to each other and to the public switched telephone network (PSTN) over 2M transmission media. It is widely used in product showcase and various communication scenarios.

IDM DXC5200 240-group E1 time-slot cross-connect equipment supports up to 240 standard E1 transmission interfaces in full configuration, with 64K time-slot non-blocking cross-connection among the 240 E1 groups within the unit; key modules such as the main control card and power card adopt dual-board mutual backup, and multiple clock modes are available to meet the clock requirements of various application environments. As a core time-slot cross-connect device under Raytrans, this product flexibly adapts to government private network optical fiber communication solutions and military emergency communications vehicle solutions, and is a trusted PCM equipment choice for optical multiplexer manufacturers and SDH equipment manufacturers.

Key specifications at a glance: 240-group E1 · 64K non-blocking cross-connection · dual-board mutual backup · DC/AC dual power supply · 2.048Mbps E1 · PCM30/32 channel-associated signaling

What kind of device is 240-group E1 time-slot cross-connect equipment?

IDM DXC5200 240-group E1 time-slot cross-connect equipment is circuit-mode transmission equipment designed for industrial private networks and high-capacity service access nodes. The unit consists of a main control card, power card, E1 service card, network management card and test card, with hardware based on dedicated large-scale integrated circuit design. The chassis is a 19-inch 3U standard structure, providing 2 power card slots, 2 main control card slots and 11 service card slots.

A single E1 service card provides 24 E1 interfaces wired through European-style sockets, and the fully configured unit accesses 240 standard E1 transmission interfaces. One side of the equipment connects to E1 lines, while the other side provides service interfaces such as audio, V.35 and RS-232. Audio voice channels are carried in 64Kbps time slots, and data services occupy time slots at N×64K bandwidth.

Figure 1: Front view of the IDM DXC5200 240-group E1 time-slot cross-connect equipment chassis and service card slots

The typical use of IDM DXC5200 240-group E1 time-slot cross-connect equipment is as a common cross-connect node in a private network: the uplink interfaces with transmission equipment over E1, while the downlink accesses services such as telephones, low-speed data and V.35 synchronous data. The equipment performs 64K time-slot-level transfer and multiplexing, so that a single E1 carries voice and data simultaneously. The 240 E1 groups are centrally scheduled within the same chassis, replacing the previous practice of laying dedicated circuits one by one in a point-to-point manner, so private network capacity expansion no longer depends on adding patch panels and manual patch cords.

What can this equipment do? Core functions at a glance

IDM DXC5200 240-group E1 time-slot cross-connect equipment integrates cross-connection, service access and operation and maintenance capabilities on the same platform. The functions and their descriptions are listed in the table below.

How is 64K time-slot non-blocking cross-connection among 240 E1 groups implemented?

How 64K time-slot non-blocking cross-connection among 240 E1 groups is implemented depends on cross-connect granularity and matrix resources: IDM DXC5200 240-group E1 time-slot cross-connect equipment uses 64K time slots as the cross-connect granularity, and the cross-connect matrix establishes an independent connection relationship for each of the 32 time slots of every E1. Any input time slot can be connected to any output time slot, and connections do not compete for resources with each other, so adding or adjusting circuits does not block services in operation due to internal matrix conflicts.

Knowledge block: 64K time-slot cross-connection under the PCM30/32 frame structure. PCM30/32 is the frame structure standard for the E1 base group, with 32 time slots per frame. Each E1 carries 30 usable 64K service time slots, of which TS0 is used for frame alignment and alarms, and TS16 is used for channel-associated signaling. The E1 interfaces of IDM DXC5200 240-group E1 time-slot cross-connect equipment use a 2.048Mbps bit rate and HDB3 line coding, comply with the ITU-T G.703 standard, and perform cross-connect configuration at 64K time-slot granularity. Service scheduling among the 240 E1 groups no longer depends on manual patch cords and laying dedicated circuits one by one.

How 240-group E1 non-blocking cross-connection is configured depends on service planning: cross-connection relationships are delivered one by one in the form of a configuration table, specifying the input E1 channel and time slot and the output E1 channel and time slot; during network capacity expansion or service migration, only the time-slot cross-connect table is adjusted, while transmission lines and external equipment remain unchanged. The network management card can set the signaling format for any 64K time slot among the 240 E1 groups, and collect TS16 signaling formats from third-party manufacturers online and save them automatically, achieving interconnection of telephone services between PCM equipment from different manufacturers.

How does PCM30/32 channel-associated signaling interconnect with existing network equipment?

How PCM30/32 channel-associated signaling interconnects with existing network equipment lies in the dual consistency of signaling mode and interface standard. Channel-associated signaling is a signaling mechanism that transmits line and voice channel status such as go off-hook, hang up, ringing and dialing together with voice time slots. In the PCM30/32 frame structure, it is transmitted synchronously through the TS16 time slot without establishing a separate signaling channel. IDM DXC5200 240-group E1 time-slot cross-connect equipment supports channel-associated signaling, so telephone services can pass transparently through the cross-connect node and intercommunicate with existing PCM switching equipment.

Interfacing with existing network E1 equipment depends on consistency at the interface level. The E1 interfaces of IDM DXC5200 240-group E1 time-slot cross-connect equipment comply with the ITU-T G.703 standard, with a bit rate of 2.048Mbps and HDB3 line coding, and can operate in either 75Ω coaxial or 120Ω balanced impedance form. The frame structure and signaling mode are consistent with existing PCM30/32 equipment, so upgrade scenarios usually do not require replacing the opposite-end equipment or changing the existing network transmission system.

How are the rate steps configured for V.35 and RS-232 data interfaces?

V.35 and RS-232 are the two interface forms through which IDM DXC5200 240-group E1 time-slot cross-connect equipment carries data services. The V.35 interface uses an RJ-45 form, with electrical characteristics compliant with ITU-T V.35 recommendations and a terminal interface compliant with ISO2593; the transmission rate is set as n×64Kbps, where n ranges from 0 to 31, so a service can occupy 0 to 31 consecutive 64K time slots. The RS-232 interface has a transmission rate of asynchronous ≤9600bps or synchronous 64Kbps, with electrical characteristics compliant with the CCITT V.28 protocol, and is used to carry low-speed asynchronous data.

Data services and voice services share the same cross-connect matrix in the IDM DXC5200 240-group E1 time-slot cross-connect equipment. After V.35, RS-232 and audio voice channels enter the equipment, they are uniformly split into 64K time slots and then allocated to designated time slots of target E1 channels according to service planning, so that multiple services can share the same E1 channel. The chassis supports insertion of 64K and n×64K service boards, each slot can provide 8 or 10 channels of 64K services, and the service types and quantities are configured per project.

Technical Specifications

Figure 2: E1 interface cabling and private network cabinet installation of the IDM DXC5200 240-group E1 time-slot cross-connect equipment

E1 Interface Parameters (ITU-T G.703)

Audio and EM Interface Parameters

Data Interface Parameters (V.24 and V.35)

Power Supply and Environmental Parameters

Differentiated Value: 240 Groups of E1 · 64K Non-Blocking Cross-Connection · Dual-Board Mutual Backup · DC/AC Dual Power Supply

The capabilities and customer value of the IDM DXC5200 240-group E1 time-slot cross-connect equipment can be reviewed item by item in the table below.

Typical Application Scenarios

The IDM DXC5200 240-group E1 time-slot cross-connect equipment suits industrial private network scenarios that use E1 as the transmission medium and need to centrally schedule voice and data services onto the same channel. Common deployments include substation service aggregation in electric power private networks, inter-station voice channel and data upload in rail transit communication, and retrofit projects in military/government private networks that interconnect with the existing transmission system.

Electric Power Private Network: Simultaneous Voice and Data Transmission Between Substations and the Dispatch Center

Between substations, switching stations and the dispatch center in an electric power private network, there are both telephone dispatching services and low-speed data services for protection and monitoring information. The IDM DXC5200 240-group E1 time-slot cross-connect equipment aggregates the E1 channels of each site and, at the 64K time slot level, cross-connects the telephone voice channels and data time slots separately to the corresponding E1 time slots of the dispatch center, so one E1 carries voice and data simultaneously and the number of private network lines is reduced. Channel-associated signaling enables telephone services to interconnect directly with existing PCM switching equipment, and when a site is expanded, only the time-slot cross-connection configuration needs to be adjusted without laying dedicated circuits again.

Rail Transit Communication: Voice Channel and Data Aggregation Between Section Stations and the Center

Section stations in rail transit communication are scattered, and voice channel and data services need to be aggregated at the central side. The IDM DXC5200 240-group E1 time-slot cross-connect equipment aggregates the E1 channels uploaded by each section station to the central cross-connect node and, by 64K time slot, allocates the inter-station voice channels and the monitoring data to the corresponding channels separately; when adding a station or adjusting service assignment, only the time-slot cross-connection configuration needs to be adjusted without laying a dedicated circuit for each station. The equipment supports both DC and AC power supply modes and can connect to AC or DC power in a trackside equipment room.

Military/Government Private Network: Channel-Associated Signaling and 75Ω/120Ω, V.35 Access to the Existing Private Network

The existing transmission system of military and government private networks is mainly based on E1 circuits, and retrofit projects require new equipment to access seamlessly without changing the existing network. The IDM DXC5200 240-group E1 time-slot cross-connect equipment supports channel-associated signaling; the E1 interface can be configured between 75Ω coaxial and 120Ω balanced according to the line form at the opposite end, and the V.35 interface rate is configured as n×64Kbps, enabling interfacing with the original PCM switching equipment, routers and multiplexers; dual-board mutual backup of the main control card and power card keeps critical modules uninterrupted, and with DC/AC dual power supply and an operating temperature of -20℃ ~ +50℃, the equipment can be deployed in field vehicle-mounted cabinets and equipment rooms with limited conditions.

How to Select and Deploy Time-Slot Cross-Connect Equipment?

To select time-slot cross-connect equipment, the requirements are usually counted first by service type: the number of E1 channels requiring cross-connection scheduling, the number of audio voice channels, and the number of V.35 and RS-232 data channels, based on which the interface configuration and time slot occupation of the PCM equipment are checked; the E1 interface impedance is selected as 75Ω coaxial or 120Ω balanced according to the line form at the opposite end, and the frame structure and signaling mode are selected as PCM30/32 and channel-associated signaling according to the existing network transmission system.

During selection, it should also be confirmed whether the cross-connect granularity is 64K time slots and whether arbitrary time slot interconnection and time slot adjustment for subsequent capacity expansion are supported, so as to avoid the time-slot cross-connect equipment being unable to expand due to limited cross-connect matrix resources after it is put into operation; the power supply mode is selected as DC/AC according to equipment room conditions, and for field and unattended sites the operating temperature and humidity range should also be checked. The complete configuration list, interface board configuration and networking solution of the IDM DXC5200 240-group E1 time-slot cross-connect equipment can be confirmed with Beijing Ruiguang Jiyuan Digital Technology Co., Ltd. based on the specific project topology, and the manufacturer will provide selection and commissioning support.