UNITED24 - Make a charitable donation in support of Ukraine!


Chapter 4

Telecommunications Center, Switching, and Patch Panel Operations

4-1. General

A signal organization must improvise when it does not have enough TCC equipment. All TCCs and RATT assemblages that currently provide over-the-counter record traffic support will be phased out by 1994. They will be replaced by user-owned and -operated LDF AN/UXC-7 and the microcomputer communications terminal AN/UGC-144. The user-owned and -operated operational concept/architecture will be phased in at EAC as the TRI-TAC Block III equipment (AN/TTC-39A and DGM) are fielded. AT ECB, phase in will be synchronized with the MSE fielding schedule.

4-2. Telecommunications Center Operations

When a signal organization is short of TCC equipment, it must use available shelters or properly secured and guarded tents. However accomplished, the TCC function must be performed.

a. Fabricate a TCC using spare shelters/tents, field tables, and spare teletypewriter equipment from inoperable RATT or TCC rigs. Be sure to use the appropriate on-line cryptographic equipment. This practice is subject to the command's policies on use and modification of equipment.

b. Establish a direct wire circuit between the TCC and the RATT rig handling priority traffic. Remoting the teletypewriter allows page copy to be transmitted and received directly at the TCC without additional processing or handling by radio operator personnel.

c. Cross train staff section clerical personnel in message preparation so that message traffic can be prepared in proper format for transmission before it is processed at the TCC. This lessens the impact of a shortage of TCC resources by spreading the workload. It does place an additional training burden upon the unit by requiring more people to know how to prepare messages. Messages must be short to optimize the use of available traffic channels. (See the discussion of low-level encryption and brevity codes in Chapter 7.) TCC personnel are not expected to modify or shorten messages by applying brevity codes to the messages. TCC personnel transmit message texts exactly as they receive them; any modification or shortening of messages must be accomplished by originators. (See DA Pam 25-7 for procedures on JINTACCS message text format.)

d. Increase the quantity of air and motor messengers available to make up for lack of TCC processing and transmission facilities. (See Chapter 6.)

e. Obtain and use additional quantities of AN/TCC-14 or AN/TCC-29 assemblies (which provide a speech-plus teletypewriter capability) for better use of available voice channels. Use of off-line encryption methods increases if TCC equipment is in short supply. (Low-level encryption methods are discussed in Chapter 7.)

NOTE: When assembling or fabricating temporary TCC facilities, it is essential to use proper grounding procedures.

f. Use facsimile equipment or microprocessors to route messages and overlays to their destinations. These devices can be used over different means of communications, such as FM radio, multichannel, and other facilities.

4-3. Telecommunications Center Operations Example

a. Your brigade CP area received enemy artillery fire, seriously injuring one operator and destroying the TCC equipment.

b. What is a temporary solution pending replacements for the TCC equipment?

c. One solution is to use a RATT rig as a temporary TCC. This requires several measures not normally used.

(1) The RATT rig chosen cannot operate in its normally assigned net full time. Provisions must be made for the passage of its usual traffic by alternate means or the passage of reduced amounts of traffic by the RATT rig for limited periods of time.

(2) The RATT equipment operators involved must have appropriate ACPs, other required publications, and the training to properly process the traffic.

(3) Additional personnel must be tasked and trained ahead of time to augment the message processing capability of RATT equipment operators.

(4) Maximum use of alternate means must be made during the shortage of the TCC equipment and personnel.

(5) Other equipment with teletypewriter capabilities can be tasked to perform TCC functions. This also requires advance cross training of additional personnel in TCC procedures.

(6) Originators must make special efforts to keep messages short during the period of the TCC shortage. Message brevity is a good practice any time, but is especially valuable during periods of equipment and personnel shortages.

4-4. Tactical Facsimile Operations

TCCs are rapidly being replaced by facsimile devices that can operate with the current inventory of communications equipment. These devices are user-operated and user-installed. The user can call up the addressee, confirm the link, transmit the copy, and verify the quality without interfacing with over-the-counter TCC service. This system has been fielded in Europe and virtually eliminates record traffic at brigade and separate battalion levels.

4-5. Switching Operations

Switching equipment is in short supply in many RC units and can also be expected to be in short supply during combat operations. This presents a serious problem to all commanders and communicators; however, measures can be taken to reduce the effect of switching equipment shortages.

a. Reduce the number of local lines to various subscribers. This must be done based on the commander's established priority system considering the minimum critical needs of the unit.

b. Establish a limited number of common-user telephone points or booths in staff areas. Phone usage in these activities should be restricted to certain predesignated users.

c. Limit lower priority calls to lesser-traffic hours and limit the call length. Noncritical administrative and logistics traffic can be passed during these hours or passed over alternate means.

d. Establish hot loops within specific activities and use a ringing code to alert users. This party line approach eliminates each party being connected directly to a switchboard and reduces the switchboard load.

e. Reduce manual operator interventions. Patch (or direct wire) priority circuits from the TOC and certain other priority users directly through the multichannel radio system (or alternate means) supporting that circuit to the distant subscriber.

f. Enforce telephone discipline during critical periods. Develop a local minimize policy for use over voice communications facilities.

g. Limit sole-user circuits to two-wire configurations and eliminate sole users in four-wire patterns.

h. Use local commercial telephone systems when possible.

4-6. Patch Panel Operations

The patch panel is literally the heart of a signal center operation. The absence or loss of a patch panel presents a large obstacle to the communicator but not an impossible one. Patching service can be provided when short a patch panel.

a. Fabricate a patching facility using distribution boxes J-1077A/U. Additional J-1077A/Us are essential in overcoming the problems of a missing patch panel. A cargo trailer can be used for this purpose. Mount J-1077A/Us on boards on each side of the trailer and fabricate an operator's table at the front. (See Figure 4-1.)

(1) Maintain polarity when patching between J-1077A/Us using single strands of WF-16 field wire and labeling each connection.

(2) Develop a detailed patching log to control patching. This log would be substantially different from the normally used log due to the nature of the homemade patch facility.

(3) Mount a switchboard and phone on the operator's table for local interconnection and for circuit control and monitoring.

b. Use distribution box J-2317A/U or terminal box TA-125 as an alternative to using J-1077A/Us. The TA-125 cannot be directly connected to 26-pair cable but does provide a flexible method of interconnecting circuits. Short runs of WF-16 can be made from the terminals of the signal entrance boxes of various communications assemblages to the locally constructed patching facilities using distribution boxes J-1077A/U or J-2317A/U, or terminal box TA-125.

c. Use additional SB-22 switchboards, if available, to patch circuits on a limited basis. Their limited capacity severely restricts their use as patches; but, when used in conjunction with carefully controlled direct wiring between assemblages, they provide a measure of flexibility.

d. Have units that support a standard troop structure develop a prepatched board to handle known requirements. This leaves other limited patching facilities to handle new or changing requirements.

4-7. Patch Panel Replacement Example

a. You are a platoon leader. Enemy action has destroyed the patch panel. There are no casualties since the operators had time to take cover before the patch panel was hit. Replacements for the damaged cables are available.

b. How do you get your circuits operational pending receipt of another patch panel?

c. A possible solution is to establish a temporary patching facility using junction boxes such as J-1077A/U or J-2317A/U.

(1) Junction Box J-2317A/U is preferred since it terminates four each 26-pair cables and is not wired normal through as is the J-1077A/U. Consequently, the J-2317A/U is highly useful as a temporary patch facility.

(2) Patching is accomplished using lengths of field wire. Special patch records must be made to record these unusual field wire patches.

(3) Special attention must be given to patching the critical circuits first. Your systems control records will indicate these.

NOTE: Special attention must be given to maintaining proper polarity (in addition to RECEIVE-SEND pair transposition) when patching using this method.

Join the GlobalSecurity.org mailing list