IDM OMP200-30E Ultra-Broadband Integrated Service Optical Multiplexing Equipment

IDM OMP200-30E ultra-broadband integrated service optical multiplexing equipment is a 250M optical multiplexing device developed by Beijing Ruiguang Jiyuan Digital Technology Co., Ltd. (Raytrans). It is used to carry telephone voice, Ethernet data and E1 leased-line services simultaneously over a single optical fiber line, and is an integrated service access device for multi-service scenarios.

The device adopts the PCM30/31 format and performs multiplexing and demultiplexing through an optical fiber channel compliant with the G.703 standard. With one unit deployed at each end, the pair works together to aggregate voice and data from dispersed sites into the central equipment room for unified access. As a mature PCM equipment, it reuses existing cabling and interface types at the site side, and commissioning usually requires no change to the configuration of the upper-level switching equipment, which facilitates quick product showcase and service rollout. The device is also commonly used in government private network optical fiber communication solutions and military emergency communications vehicle solutions. As a typical product of the optical multiplexer manufacturer Raytrans, it handles last-mile integrated service access.

Key specifications at a glance: Optical port SFP (single-mode, multimode optional) · Optical fiber rate 250M · Wavelength 1310nm/1550nm · Receiver sensitivity better than -24dBm · E1 2048Kbps HDB3 transparent transmission (ITU-T G.703, 75Ω, PCM30/31) · Ethernet RJ45 10M/100M/1000M adaptive · Power supply DC-48V/AC220V dual power supply · Overall power consumption ≤100W

What is a 250M optical multiplexing equipment

A 250M optical multiplexing equipment is a transmission device that packs multiple types of interface services into the same optical fiber channel. It is used in pairs: one end multiplexes voice, data and leased-line services onto the optical path, and the other end demultiplexes them and restores them as they are to the existing switches, protection devices or office network according to their respective interface standards. From the perspective of product showcase, this type of PCM equipment is a typical form of integrated service access device. As an optical multiplexer manufacturer, Raytrans has accumulated substantial experience in this product category, and IDM OMP200-30E is one of its optical multiplexing equipment offerings for private network scenarios.

The 250M optical channel of IDM OMP200-30E carries 30 voice time slots at 64Kbps, E1 channels and Ethernet data. The three service types each occupy an independent channel inside the device and do not alter each other's encoding or frame structure. Voice is arranged into the primary group frame according to PCM30/31, E1 is transparently transmitted at 2048Kbps with HDB3, and Ethernet is encapsulated independently. Existing devices at the peer end can usually be connected without configuration changes.

Figure 1: Front view of the IDM OMP200-30E unit, showing the layout of telephone interfaces and operating alarm indicator LEDs on the front panel

The device provides 2 250M SFP optical interfaces, which can be configured as dual-fiber mutual backup so that services are switched to the standby optical path when the primary optical path is interrupted. The 250M optical rate leaves margin for the combined load of 30 voice channels, E1 and gigabit Ethernet, so ordinary dispatch sites do not need to repeatedly calculate bandwidth.

What services can one device carry

As a PCM30 multiplexer, IDM OMP200-30E provides five capabilities in one device: optical fiber transmission, telephone voice, E1 channels, Ethernet access and dual power supply, replacing the separately deployed voice optical multiplexers and E1 uplink devices of the past. The function items and corresponding standards are listed in the table below:

Function	Description
250M optical fiber transmission	Optical interface is SFP, optical fiber rate 250M, single-mode (multimode optional), wavelength 1310nm/1550nm; one optical fiber carries voice, Ethernet and E1 services simultaneously
Telephone voice access	Provides 30 telephone interfaces as defined by the standard, audio range 300Hz~3400Hz, ITU G.711 A-law compression, loop current 25mA per channel
E1 channel transparent transmission	Bit rate 2048Kbps, line code HDB3, compliant with ITU-T G.703, impedance 75Ω, frame structure PCM30/31, transparent transmission does not change time slot content
Gigabit RJ45 Ethernet	RJ45 electrical port, transmission rate 10M/100M/1000M, compliant with IEEE802.3, full/half duplex adaptive, can be directly connected to in-station switches
Dual optical port mutual backup	Provides 2 250M SFP optical interfaces; in dual optical port configuration, provides optical port 1+1 protection, and services are switched to the standby optical path when the primary optical path fails
Dual power supply redundancy	Supports DC-48V and AC220V dual power supply access, overall power consumption ≤100W, loss of one power feed does not affect service operation
Network management and alarms	Provides a standard SNMP network management interface; the enclosure is equipped with a function control switch and alarm indication for remote monitoring and on-site troubleshooting

The PCM30 transparent transmission item in the table is key to compatibility with existing private networks: time slot content is delivered to the peer end as it is, so dispatching exchanges, relay protection devices and existing PCM equipment can all be directly connected without reworking data due to transmission equipment replacement. During on-site commissioning, first confirm that the PCM30/31 format is consistent at both ends, then check the E1 time slot allocation. In government private network optical fiber communication solutions and military emergency communications vehicle solutions, Raytrans often uses this type of integrated service access device as the access node for voice and E1 services, working with optical multiplexing equipment to extend channels between sites.

Key Specifications

The technical specifications of IDM OMP200-30E cover six parts: optical interface, E1 interface, Ethernet interface, telephone voice interface, power supply and consumption, and environmental conditions. Key specifications are listed in the table below. Values are subject to product documentation and factory testing; verify each item against the actual configuration during project calculation.

Item	Parameter/Specification	Description/Applicable Conditions
Optical interface type	SFP	Pluggable optical module, easy to replace by distance and to spare
Fiber mode	Single-mode (multimode optional)	Selected according to line distance and fiber core conditions
Optical fiber rate	250M	Shared by voice, Ethernet and E1 services
Wavelength	1310nm/1550nm	Two wavelengths selectable
Transmit optical power	-1~-3dBm	Typical single-mode value; subject to actual measurement with an optical power meter
Receiver sensitivity	Better than -24dBm	The link loss budget can be calculated on this basis
E1 bit rate	2048Kbps	Line code HDB3
E1 standard protocol	Supports ITU-T G.703	Standard E1 interface specification
E1 impedance	75Ω	Corresponds to coaxial 75Ω interface
E1 frame structure	PCM30/31	Primary group frame structure
E1 mode	Transparent transmission	Services are transmitted as they are, without changing time slot content
Ethernet interface type	RJ45	Gigabit RJ45 electrical port form
Ethernet transmission rate	10M/100M/1000M	Compliant with IEEE802.3, full/half duplex/adaptive
Voice audio range	300Hz~3400Hz	Telephone voice channel bandwidth
Voice impedance	Three-element complex impedance 200Ω+560Ω//0.1μF	Telephone subscriber line interface standard
Voice compression	ITU G.711 A-law	64Kbps PCM encoding
Voice loop current	25mA per channel	Feeding capability of each voice channel
Power supply mode	DC-48V /AC 220V/dual power supply	Dual power supply access improves power supply reliability
Overall power consumption	≤100W	Overall value including service cards and optical modules
Operating temperature	0ºC～40ºC	Equipment room and temperature-controlled cabinet environments
Humidity	≤90% (non-condensing)	Upper limit of relative humidity

Figure 2: Rear panel photo of the IDM OMP200-30E, showing the layout of SFP optical ports, E1 coaxial interfaces and dual power supply terminals

The optical interface uses pluggable SFP modules, with single-mode as standard and multimode optional, two wavelengths selectable at 1310nm/1550nm, transmit optical power of -1~-3dBm and receiver sensitivity better than -24dBm. In engineering, modules are selected according to fiber core conditions and line loss, which adapts to different inter-station distances better than replacing the entire unit. As an optical multiplexer manufacturer, Raytrans provides fairly complete support for module selection and spare parts for this series of optical multiplexing equipment, making it easy to configure by distance grade in government private network optical fiber communication solutions.

How does a 250M optical fiber channel remain stable under long-distance weak light

The stability of a long-distance link depends on the link loss budget, not just the nominal rate. The transmit optical power of IDM OMP200-30E is -1~-3dBm and the receiver sensitivity is better than -24dBm; the loss margin left between the two ends can cover the attenuation and splice point loss of a longer single-mode link. During selection, include the optical cable length, number of connectors and patch cord loss together, then decide the distance grade of the SFP module.

The link calculation method is to first measure the received optical power with an optical power meter, then compare it with the sensitivity threshold, leaving a margin of 3dB or more to cope with aging and temperature changes. When the received optical power approaches the threshold, first clean the flange and patch cord end faces; if it is still insufficient, switch to a module with a higher power budget rather than relying on transmit power. In military emergency communications vehicle solutions, where optical cables are temporarily laid and connectors increase after the vehicle moves, calculating the margin by the above method is particularly necessary. The dual optical port 1+1 protection of this PCM equipment from Raytrans can also switch services to the standby optical path under weak light or fiber breakage, reducing on-site troubleshooting pressure.

How to connect dual power supply redundancy to suit unattended sites

Dual power supply redundancy means feeding two independent power feeds to the two power input terminals respectively, so that services are maintained by the other feed when either one loses power. As a PCM equipment for site access, IDM OMP200-30E supports three power supply modes: DC-48V, AC220V and dual power supply, with overall power consumption ≤100W. The -48V DC and 220V AC mains power commonly used in communications equipment rooms can each occupy one feed.

The wiring and commissioning of dual power supply access are checked item by item in the following four steps, each corresponding to an on-site observable criterion. From checking the power supply type before power-on to verifying voice, E1 and Ethernet services after power-on, they form a complete commissioning chain, and subsequent maintenance can be rechecked in the same order to locate problems.

• Before power-on, check the site power supply type against the device markings, and confirm the -48V polarity wiring and the 220V wiring terminals are correct;
• Check the protective grounding and terminal crimping to avoid loose connections and overheating;
• Draw the two power feeds from different distribution circuits to reduce the probability of simultaneous power loss;
• After power-on, observe the power and alarm indications, confirm normal received optical power, then verify voice, E1 and Ethernet services one by one.

Figure 3: Close-up of the dual power supply terminals and grounding bolt of the IDM OMP200-30E, with -48V and 220V fed independently

The value of a dual power supply optical multiplexer at unattended sites lies in reducing service interruptions caused by maintenance and switching of a single power feed. The overall power consumption of ≤100W also makes capacity calculation for in-station UPS or solar power easier to pass, without separately expanding capacity for transmission equipment.

Typical application scenarios

IDM OMP200-30E is mainly deployed point-to-point, with one unit at each end interconnected by one optical fiber; site-side services are restored at the central equipment room and then connected to existing transmission, switching and protection equipment. When a site is expanded, additional service interfaces are all that is needed, without laying new optical cables.

Electric power private network: unattended substations, one fiber carrying dispatch voice and automation data

Substations and dispatch stations usually require dispatch telephones, dedicated automation E1 lines, and in-station data channels at the same time. One IDM OMP200-30E is installed at each site, multiplexing dispatch voice, E1 channels, and Ethernet data over a single 250M single-mode fiber, so that 30-channel telephone optical multiplexers, E1 optical modems, and standalone data transmission devices no longer need to be stacked in the equipment room.

On the power supply side, DC-48V and AC220V dual power supply access is adopted, with overall power consumption ≤100W. Together with dual optical port mutual backup, services remain available when a single power supply or a single optical path fails. Voice uses ITU G.711 A-law encoding with a loop current of 25mA per channel, and can be directly connected to existing dispatch voice channel equipment.

Rail Transit: Weak-Light Long-Distance Sections, PCM30 Transparent Transmission Safeguarding Train Operation and Dispatch Voice

Distances between stations, depots, and section equipment rooms are long and there are many connectors, so the received optical power is often low. The receiver sensitivity of the IDM OMP200-30E is better than -24dBm, allowing normal optical reception under weak-light conditions. Combined with 1310nm/1550nm dual-wavelength modules selected according to section loss, it reduces repeated adjustment caused by link attenuation.

Train telephone and dispatch voice run over PCM30/31 voice channels, and E1 channels are transparently transmitted according to G.703 75Ω, so existing signal and dedicated communications equipment do not need configuration changes. The Ethernet interface is adaptive at 10M/100M/1000M and can be directly connected to in-station switches, carrying office and monitoring data.

Military and Government Private Networks: G.703 75Ω Standard E1 and Gigabit Ethernet over a Single Fiber

Between remote stations and command centers, data channels often need to be added to existing private networks, and the E1 interfaces on the private network side are mostly 75Ω coaxial. The E1 interface of the IDM OMP200-30E is designed for ITU-T G.703, 75Ω, PCM30/31 transparent transmission, and can be directly connected to existing PCM equipment and private network switches, while the gigabit RJ45 electrical port provides an Ethernet channel.

The device is a standard 19-inch 1U chassis with an SNMP network management interface and alarm indication, allowing the central equipment room to remotely check the status of remote stations and reducing on-site inspection. The operating temperature is 0ºC–40ºC and the humidity is ≤90% (non-condensing), making it suitable for deployment in temperature-controlled equipment rooms or communication vehicle cabinets.

Figure 4: IDM OMP200-30E point-to-point networking schematic, with both ends interconnected via 250M single-mode fiber and connected to a dispatching exchange