IDM MSTP-YZ155 Narrowband/Broadband Integrated Optical Multiplexer

The IDM MSTP-YZ155 dual-STM-1 wideband/narrowband integrated optical multiplexer is a new-generation SDH device developed by Beijing Ruiguang Jiyuan Digital Technology Co., Ltd. (Raytrans) for military requirements, based on SDH/MSTP and PCM technologies. It carries both wideband (Ethernet) and narrowband (E1, voice, low-speed data) services over the same pair of optical fibers. As a professional SDH equipment manufacturer and optical multiplexer manufacturer, Raytrans positions this device for emergency communications and private network transmission scenarios. The device provides two STM-1 optical interfaces and supports various service cards as required, aggregating site-side E1 circuits, Ethernet, telephone and data services into a single optical transmission network. It delivers reliable communication protection for field and private network communications and serves as a core transmission node in military emergency communications vehicle solutions.

The IDM MSTP-YZ155 targets three scenarios: military field communications, electric power and rail transit private networks, and unattended field sites. It can carry wideband and narrowband services uniformly in emergency communications. The unit uses industrial-grade components with comprehensive electromagnetic compatibility and interface protection design. Service connectors uniformly adopt circular/aviation connectors, offering water resistance, good sealing and shock resistance, making the device suitable for long-term operation under various temperature and humidity conditions, electromagnetic environments and mobile conditions in the field. The device has built-in SDH equipment and optical transmission equipment capabilities, and can interface with government private network optical fiber communication solutions, meeting private network requirements for the stability and security of optical transmission equipment.

Key specifications at a glance: Dual STM-1 optical ports (155M/155M) · 40km transmission · 16-channel E1 arbitrary add/drop · 4-channel isolated Ethernet · 30-channel 64K voice and data services · Overall power consumption ≤50W

Figure 1: Overall appearance of the IDM MSTP-YZ155 dual-STM-1 wideband/narrowband integrated optical multiplexer, with front panel optical ports and status indicator LEDs

What kind of device is a dual-STM-1 wideband/narrowband integrated optical multiplexer?

A dual-STM-1 wideband/narrowband integrated optical multiplexer is a composite transmission device that integrates SDH/MSTP optical transmission and PCM multi-service access in a single unit, equipped with two STM-1 optical interfaces. The wideband side carries Ethernet services, while the narrowband side carries E1 circuits, telephone and low-speed data services. Both service types share the same pair of optical fibers, so a site does not need separate equipment and lines for wideband and narrowband. In emergency communications scenarios, this integrated design significantly shortens on-site commissioning time, as a single device meets both wideband data and narrowband voice access requirements.

The IDM MSTP-YZ155 adopts a modular card-based structure. Installing the corresponding interface cards as required by the project enables the relevant services. It complies with the timing requirements of ITU-T G.813 and provides comprehensive network management functions, enabling online real-time monitoring of operating status and alarms. Compared with ordinary optical multiplexers that have only one optical port, the two STM-1 optical ports provide the hardware foundation for various networking topologies such as chain and ring networks, and offer a reliable transmission platform for rapid networking and flexible dispatching in military emergency communications vehicle solutions.

Dual STM-1 optical ports, 40km transmission: why field links endure longer distances

The 40km transmission capability comes from the optical interface's receive/transmit specifications and redundancy design. The two STM-1 optical interfaces of the IDM MSTP-YZ155 have a receive/transmit rate of 155M/155M, a transmit optical power of -15 to -8dBm, and a receiver sensitivity better than -32dBm. The transmission distance under standard single-mode configuration is 40Km; for longer lines, long-distance optical modules can be installed to achieve longer optical fiber transmission.

A receiver sensitivity better than -32dBm means the receiver retains a larger power margin under the same line loss. Field optical cables have many splice points, and additional loss from aging, sand and dust, and construction disturbance is difficult to avoid entirely. The greater the power margin, the less likely the link is to experience bit errors and momentary interruptions under conditions of long distance, large temperature differences and numerous connectors. This is the basis for field links enduring longer distances more reliably, and is also one of the core requirements for optical transmission equipment at emergency communications sites.

The two STM-1 optical ports support three networking approaches: point-to-point, chain and ring. They can be networked jointly with centralized MSTP to form complex networks such as tangent rings and branch rings. In ring networking, if a section of optical cable on the ring is interrupted, services can be rerouted in the other direction to an available path, ensuring continuity of inter-station voice, data and monitoring services. This self-healing protection capability is particularly important in military emergency communications vehicle solutions, ensuring communication links are not interrupted in complex battlefield environments.

How do 16-channel E1 arbitrary add/drop and 4-channel isolated Ethernet dispatch site services

The core value of a 16-channel E1 arbitrary add/drop circuit optical multiplexer lies in flexible add/drop of site services. The IDM MSTP-YZ155 supports arbitrary add/drop of 16 E1 tributaries at any point on the ring network. Any E1 channel can be accessed or extracted nearby as required by the service, eliminating the need to lay separate backhaul lines for each site. The E1 bit rate is 2048Kbps, the line coding is HDB3, it complies with ITU-T G.703, the impedance is selectable between 75Ω/120Ω, the frame structure is PCM30/31, and channel-associated signaling (CAS) is used.

The wideband side provides 4 physically isolated Ethernet channels. Each service channel is independent of one another and invisible to the others, and bandwidth can be bundled and arbitrarily allocated as N×E1, merging the bandwidth of multiple E1 channels for use by the same Ethernet service. This combination allows a single device to carry low-bandwidth monitoring and office data while also expanding capacity for services that temporarily require higher bandwidth. The Ethernet interface type is RJ-45, compliant with IEEE802.3, the operating mode is full/half duplex adaptive, and the transmission rate is N×2.048Mbps (N≤50). In government private network optical fiber communication solutions, this physical isolation mechanism effectively safeguards the information security of different service systems.

Figure 2: Close-up of the circular/aviation connector service interfaces and plug-in card service boards of the IDM MSTP-YZ155 wideband/narrowband integrated optical multiplexer

Which interfaces are available for narrowband voice and low-speed data

Narrowband services cover 30 channels of 64K and N×64K voice and data services, with a complete range of integrated service types, more than 20 in total. The voice side provides FXO and FXS interfaces, with an audio range of 300Hz to 3400Hz, compression ITU G.711 A-law, impedance of three-element complex impedance 200Ω+560Ω//0.1μF, and loop current of 25mA per channel. The EM2/4-wire interface has a balanced impedance of 600Ω and a return loss of no less than 18dB.

The low-speed data side provides V.24 and V.35 interfaces. The V.24 interface has an asynchronous rate of ≤9600bps and a synchronous rate of 64Kbps, with electrical characteristics compliant with the CCITT V.28 protocol. The V.35 interface has a transmission rate of n×64Kbps (n=0 to 31), with electrical characteristics compliant with ITU-T V.35 recommendations and a terminal interface compliant with ISO2593. The modular card-based structure allows various interfaces to be combined as required; subsequent capacity expansion only requires adding or replacing service cards, without replacing the entire unit. For on-site command and dispatch in emergency communications, the rich narrowband interfaces enable rapid connection to various voice terminals and low-speed data devices.

What are the core functions of the IDM MSTP-YZ155

The IDM MSTP-YZ155 organizes its functions around three threads: optical transmission, wideband and narrowband service access, and reliable networking. The main functions are listed in the table below.

IDM MSTP-YZ155 technical specifications

The main technical specifications of the optical interfaces, E1, Ethernet, voice and data interfaces, and power supply environment are listed in the table below, which can be used to verify selection parameters.

As a professional optical multiplexer manufacturer, Raytrans has accumulated rich experience in the R&D and manufacturing of SDH equipment and optical transmission equipment, and its identity as an SDH equipment manufacturer enjoys a good reputation in the industry. IDM MSTP-YZ155 is a product showcase built for military emergency communications vehicle solutions, government private network optical fiber communication solutions and various emergency communications scenarios, integrating SDH equipment, optical transmission equipment and optical multiplexers to provide users with complete support from product showcase to solution implementation.

Typical Application Scenarios in Military Field and Private Networks

Military Field Communications: Narrowband and Broadband Services Backhauled over the Same Fiber under Mobile Conditions

Emergency communications equipment under field conditions moves with troops during relocation and must withstand vibration and shock, rain, sand and dust, and wide temperature variations. IDM MSTP-YZ155 adopts aviation connector sealed, waterproof and shock-resistant service interface design, with industrial-grade components in the core circuits; its industrial-grade -50℃～+85℃ wide-temperature design covers severe cold and high-temperature field environments, adapting to harsh mobile environments, making it a reliable transmission platform in military emergency communications vehicle solutions. Chain or ring links with dual optical ports are deployed between field command posts, communication vehicles and forward sites; when any section of optical cable is damaged, voice and data services can switch over to the other direction of the ring, providing continuous support for command communications.

Electric Power and Rail Transit Private Networks: E1 and Ethernet Services Aggregated over One Fiber at Sites along the Line

Electric power and rail transit private networks have distributed sites along the line, large spacing between stations and obvious environmental differences. IDM MSTP-YZ155 builds line protection with dual STM-1 optical ports, uniformly carrying 2M (E1) dispatch services, Ethernet production services and inter-station telephone services; 16 E1 channels with arbitrary add/drop allow each site to add/drop circuits as required, and 4 physically isolated Ethernet interfaces can transmit services of different security levels, such as train control and video surveillance, in separate zones, reducing mutual interference. The equipment is installed in cabinets along the line, and its industrial-grade wide temperature and shock resistance adapt to the deployment conditions of outdoor box-type substations and remote station sites, meeting the requirements of government private network optical fiber communication solutions for service aggregation across multiple sites along the line.

Unattended Field Sites: Remote Network Management and Low-Power Operation

Unattended field sites usually have no permanent duty personnel, and power supply and inspection conditions are limited. IDM MSTP-YZ155 has an overall power consumption of ≤50W and an operating temperature of -30℃～+50℃, supports both AC220V and DC-48V power supply modes, and can connect to the existing power supply of field cabinets; the equipment provides complete network management functions, enabling online real-time monitoring of operating status and alarms, so O&M personnel can grasp the conditions of remote stations at the central station and reduce on-site inspection frequency.

Figure 3: Application diagram of IDM MSTP-YZ155 narrowband and broadband integrated optical multiplexer in field and private network ring networking