Military

5-1. The communications systems and procedures at the M109A6 battalion level do not differ significantly from those in other M109A5 battalions. FM 6-20-1 outlines communications procedures and nets any cannon battalion uses as it executes its mission of providing fire support to the maneuver force. In a Paladin battalion however, greater emphasis is placed on the use of radio systems at the battery level and below.

5-2. The increased number of radios, along with a reduction in personnel and equipment available to install and service wire, requires changes in the traditional way the communications section, as well as the battery as a whole, approaches its mission. The dispersion of communications assets within the unit increases the need for mobility and map reading skills among the members of the communications section. If wire is used, especially if the battery wishes or is directed to enter the mobile subscriber equipment (MSE) system, the BC must plan and coordinate with the battalion signal officer for whatever external support is required. If a unit's modified table of organization and equipment does not provide for a 31U (radio repairer), the battalion SOP must address the shortage and provide a solution.

5-3. The firing battery normally operates on three secure external radio nets:

• Battalion command net (very high frequency (VHF)-frequency modulated (FM)-voice (V)).
• One of three battalion fire direction (FD) nets (VHF-FM-digital (D)).
• Battalion A/L net (VHF-FM-V).

5-4. The battery also operates five secure internal radio nets:

• Battery command (VHF-FM-V).
• Platoon command (VHF-FM-V) X 2.
• Platoon FD (VHF-FM-D) X 2. Each platoon operates on its own assigned FD net to facilitate automated C2.

5-5. This net enables battery personnel to pass operational and admin/log traffic. The battery commander may designate full time subscribers for this net.

5-6. This net enables platoon personnel to pass operational and admin/log traffic. Only mission essential traffic should be passed on this net. The POC operates as the net control station (NCS). Failure to practice net discipline diminishes the effectiveness of the battery's command and control.

5-7. This net enables each POC (BCS) to communicate digitally with its howitzers. As a matter of SOP, the net frequency and BCS address of the alternate POC should be provided to each COS with instructions to establish digital communications with his alternate POC if his primary POC becomes inoperative or mutual support is required. The operational POC acts as the NCS in this situation. Howitzer section chiefs must avoid masking their radio communications with terrain features or man-made objects as they select firing positions or make survivability moves.

5-8. Figure 5-1 illustrates the radio net structure and SINCGARS equipment for a firing battery in a Paladin battalion. Table 5-1 provides an example Paladin firing battery combat net radio matrix.

5-9. Power output and planning ranges for SINCGARS are shown in Table 5-2.

5-10. The electronic warfare (EW) threat must always be taken into account. Each element of the battery must operate on the minimum power needed to communicate effectively

5-11. Before communicating digitally, personnel must make various software settings in the AFCS and LCU. Many of these settings should be part of the unit TSOP.

5-12. The values set for this function allows each howitzer access to the battery internal FD net. When the LCU transmits data to all howitzers, it is a single broadcast message. If the net access delay time were the same for all howitzers, each would be competing for the same space in time to return an acknowledgment to the LCU. If this were to happen, no AFCS would be able to access the net. By staggering the time for net access, each AFCS has its own space in time to respond to LCU messages.

5-16. Table 5-3 provides an example of communications sequencing used to manage the platoon FD digital net (referred to as net access delay time) in order to maintain communications between the POC and the howitzers' AFCS.

5-13. Gun key time is a software setting in the AFCS which allows the radio to key up to full power before digital traffic is transmitted.

5-14. The LCU can transmit to all howitzers with a single transmission. Each howitzer must have the same address as found in the SYS;SBT. This address is valid only for the LCU. Any attempt to use it otherwise causes an error at the LCU, or the AFCS responds with an unable to execute (UTE) message.

5-15. This address is used when linking a single howitzer with a TA asset capable of digital communications (i.e., HTU, FED, OH-58D, or radar). This address must be different for each howitzer if more than one howitzer is going to be linked. (Note: AFCS will not allow duplication of the physical address.)

5-17. Shown below (Figures 5-2 and 5-3) are examples of the communications parameter card used to establish both voice and digital communications between the POC and the howitzers during initialization, as well as provide them with backup information in the event that the primary BCS becomes inoperable. This information is included in the unit SOPs and is given to the howitzers prior to starting operations.

5-18. Use of wire in a Paladin battery is usually limited to those periods when a howitzer's radio communication is degraded and it must connect with another howitzer, FAASV, or the POC in order to continue operating or when radio listening silence is imposed by the higher headquarters. Connecting by wire to another howitzer or a FAASV allows voice intercom communications (AN/VIS-3). Connecting to the POC provides both voice and digital communications (if two wire lines are laid). Priority in establishing communications is digital followed by voice.

5-19. Only one method may be used to establish the digital link over land line. For each howitzer, this is done by connecting one end of the DR-8 wire to the howitzer digital binding post and the other end to the POC LCU wire line adapter binding post. The limitations associated with this method are the amount of available wire and the time it takes to install, maintain, and recover the wire line. Wire cannot be hot looped.

5-20. If radio listening silence is imposed, an alternate means of communications (such as wire, messenger, or signals) must be used. Given the constraints on wire, personnel, visibility, mission, time, and the requirement to maintain digital communications between the guns and the POC, the procedures below should be considered when developing the unit TSOP:

• If required, move howitzers to within 1/4 mile (or less) of the POC or platoon terminal board (TM-184) and use DR-8 wire lines.
• Establish a battery wirehead as a connection point for the POCs.
• Consider use of wire line adapter (HYX-57/TSEC for wire line security and remoting.
• Mark lines or provide line route maps for wire repair or recovery operations, if they are used.
• Use other available means (messenger, visual signals) to facilitate communication needs.
• Establish communications with adjacent units, left to right or higher to lower, as applicable.