TITLE OF INSTRUCTIONAL EVENT: DIVISION/CORPS COMMUNICATIONS 10 JAN 96

NOTES PRESENTATION

1. INTRODUCTION:

a. Tie-in: You have learned enough about MI operations and how they apply to Army operations to realize how important communi cations can be. During Operation Desert Shield, tactical commanders were often frustrated by a lack of timely intelligence products that applied specifically to their area of operations. It was discovered that many people in the MI community were not knowledgeable of the communications architecture which existed to support the required information flow. Once this shortcoming was identified and corrected intelligence products began to flow with greater reliability.

b. Purpose: As an MI officer you stand a very good chance of being assigned to a tactical unit. Wherever you go, you will be responsible for gathering, processing and disseminating information. That is what your branch is all about. You need to be aware of the communications systems which are avail- able to you at any given echelon which support your dissemination needs.

c. Scope: This block of instruction pro- vides an overview of the communication architecture which exists in support of Army operations and an overview of the current Area Common User System which is employed for use at corps and below.

d. Safety Considerations: There are no special safety considerations for this class. RAC: IVE-LOW.

e. Procedure: I will provide you with applicable information on communications. You should be prepared to answer any questions that I may ask. I would encourage you to share any relevant experiences which you may have had.

2. DEVELOPMENT Show ATCCS a. Army Communications Architecture.

(1) This slide shows a graphic model of the Army's communications architecture which has evolved in order to support the command and control information needs of tactical units. Army tactical units are grouped together into five Battlefield Functional Areas (BFA's). They are: Maneuver, Fire Support, Air Defense Artillery, Intelligence/Electronic Warfare, and Combat Service Support. Units are grouped according to their unique battlefield informational needs. Each BFA has a distinct mission and generates distinct information or informational needs which must be communi- cated amongst the other BFA's. For example, the mission of the fire support unit is to provide effective indirect fires to supported units. In order to do this, information exchange must occur with maneuver units as they report positions and request fire, with IEW assets for enemy disposition and targeting information, with supporting ADA elements to ensure adequate air defensecoverage, and with its service support units for the necessary logistics support.

(2) The lines which connect the five points of the star represent the requirement for communications between the points. It can be seen that each of the BFA's must communi- cate with each of the others. The three main means of communications which support these needs are shown inside the star. Each of the three means provides for different types of requirements.

(a) Combat Net Radio (CNR) is single channel radio. It provides for short range, immediate control of mobile elements. CNR is the VRC-12 series or the new SINCGARS FM radio. CNR is the primary means of command and control at brigade and below.

(b) ACUS stands for the Area Common User System. The ACUS is the tactical telephone network that is installed on the battlefield by the Signal Corps. It is very similar to the civilian phone networks. It allows detailed coordination and planning to occur over long distances because the system covers the entire battlefield. The ACUS is the primary means of communication at division and above. At corps and below, the ACUS is com- posed of the new Mobile Subscriber Equipment (MSE) and at echelons above corps the older TRI-TAC equipment is used.

(c) ADDS stands for the Army Data Distribution System. This system is intended to provide for large volume data distribution to support systems like the Forward Area Air Defense System, TACFIRE, MCS and so on. This system is to be composed of a hybrid of the Enhanced Position Locating and Reporting System (EPLRS) and the Joint Tactical Information Distribution System (JTIDS). The ADDS is not yet at the fielding stage so most of the data being distributed across the battlefield is having to go across the ACUS. This has caused some serious competition for circuits on the ACUS which was intended to carry voice and facsimile traffic. The MSE system has been retrofitted with a packet switching capability which will put all data traffic on the overhead switchboard circuits.

STUDENT CHECK: Q: Why is the ACUS the primary means of C2 at division and above? A: Because it allows detailed coordination over long distances.

Show ACUS b. Now let's talk about the Area Common User System. The ACUS is the backbone of command and control communications at division and above. It is considered the backbone because at that level there is a great deal of detailed coordination which must be accomplished and a great amount of data and information to be passed back and forth. Also, the information must be passed over long distances. From a corps rear to a division main, for example. It takes a large scale multichannel telephone system to handle that kind of traffic over long distances.

-Also, remember that the ACUS carries voice, fax, and data over its circuits. Show MSE c. The current generation of multichannel equipment which makes up the Area Common User System is called Mobile Subscriber Equipment or, MSE. Show MSE Deployment d. This slide shows a "typical" 5 division corps deployment of MSE. Each division deploys with 4 node centers, the corps deploys with 22 node centers. We will discuss node centers in depth later in the class. Show Multichannel Access e. These are the CP's at division level where you will find access to the multichannel telephone system. Each of these places will have its own switchboard for subscribers to plug their telephones into. Each of the divi- sion CP's, the maneuver brigades plus their trains, and all of the separate battalions. The signal battalion is not listed because it owns all of the MSE equipment anyway. Show LOS Radio Assemblages f. The line of site multichannel radio assemblage deployed at the locations shown on the previous slide will consist of this equipment. The number of antennas depends on the type of equipment. Equipment is sent to locations based on need. Student Check: Q: Where do you find access to the multichannel system? A: Division command posts, brigades & trains, separate headquarters. Show System Features g. Features.

- The MSE system is digital from end to end. This is a great improvement over the older generation of multichannel equipment which was analog. The new digital format ensures that circuits are "clean" from phone to phone. In other words, there is a distinct absence of noise on the MSE circuits. This is extremely important for the transmission of data.

-MSE uses something called flood search routing in order to process calls. This process allows a subscriber to keep the same phone number no matter where he moves on the battlefield. This is a feature that not even the commercial phone systems can offer us yet.

-In order for the system to be able to provide service to any given subscriber, cer- tain information regarding his terminal instru- ments must be in the memory of the computer- ized switchboards. Since it is recognized that some switchboards may not survive, this essential information is duplicated in at least one other switchboard besides the original.

-The MSE common user system interfaces with a great number of other communication systems to include the echelons above corps multi- channel equipment which is called TRI-TAC and it interfaces with our tactical satellite equipment. It can interface with the combat net radio by way of a Net Radio Interface device so that one person on a telephone can talk to another one on the FM radio. It gives access to the commercial world so that we have a readily available backup or admin/log network. And it allows us to tie into the common user systems of our NATO allies. Show Features Cont. -The system provides for line hunting groups which means that if you have several phones in one operational cell and someone calls the number of one of your phones that is busy, the switchboard will automatically put the call on one of your phones that is not in use.

-EUB stands for Essential User Bypass. This feature allows subscriber service to be transferred to a different switchboard if his local switch develops any operational problems that would result in a loss of service to a site.

-The MSE circuits are bulk encrypted at the SECRET level. Later on I will explain how you guys in the MI Corps can increase the en- cryption to the TS level for your own use.

-With the MSE equipment we have the capa- bility of remoting our line of site radio vans from command and control centers to some extent. This is a capability that many comman- ders like because it removes a major radio signature from their CP.

-The MSE equipment is also hardened against the effects of Electromagnetic Pulse (EMP). Student Check: Q: To what level is the MSE system encrypted? A: SECRET

Show Subscriber Features h. Subscriber Features.

-As a subscriber you have the standard 5 precedence levels available to you (if you are important enough). These are: Routine, Prio- rity, Immediate, Flash, and Flash Override.

-If you are going to leave your operations cell for a while to go to another cell, you can forward your calls to a number that will be at your temporary location.

-You can make conference calls to talk to more than one other subscriber at once either by dialing each party yourself (progressive) or if your phone is programmed with the capability you can have pre-programmed conference calling capability. With that, you just press the appropriate code numbers and the conference parties are dialed automatically by the switch board all at once.

-If you are very important, you may have direct access with someone. This is where you simply pick up your phone and the other phone rings automatically.

-And, if you want, the system can provide you with the ability to call selected phone numbers with only a three digit number instead of the normal 7 digit number.

Show Architecture i. Architecture. Now I want to explain to you how the MSE network is put together and how it supports the battlefield. These are the main components of the MSE system and I will explain what each one is and what it is com- posed of. Show "Slice" j. A better way to provide an area tele- phone system would be to use what is called the nodal concept. Here, a network of switching centers is established across the battlefield. Each of the switching centers is called an area signal node and they are all connected to each other by multichannel radio shots. The area nodes are all by themselves on the high ground. There are no CP's with them. The CP's are hiding down in the valleys where the enemy will have a harder time finding them. The CP's are connected to the switching network by only one or two multichannel radio shots and so besides being hidden in low areas, they all look pretty much alike. In a five division corps there would be 42 node centers.

Show Typical Node Center (1) This slide shows the equipment found at a typical node center. Node centers can be "tactically tailored". In other words they can have different equipment based on the tactical commanders needs. Show Node Center Equipment This diagram depicts a typical node center. Somewhere in the center is a switchboard which fills two HMMWV shelters. There is also a management facility with the switchboard and this is where the platoon leader and his site chief manage their assets and radio links. Around the switchboard are four line of sight radio vans are connected to the switchboard by a cable which is 1/4 mile long. There is also something called a RAU at each node center. RAU stands for Radio Access Unit and it is comparable to the civilian relay station that allows cellular telephones to interface with the nation wide switching system. I will discuss RAU's in more detail in a little bit. Notice there is the ability to install a tactical satellite interface at the node centers A satellite terminal van from the EAC signal brigade in the theater would be sent to various node centers in order to provide the ACUS with access to the tactical satellite net- work. This effectively gives all subscribers on the MSE system the capability to dial around the entire theater of operations. Also, a device called a NATO Analog Interface can be installed at a node center. This device (an NAI) allows interface between the multichannel systems of our NATO allies and the MSE system. Student Check: Q: What are the major items at the node center? A: Switchboard, LOS vans, RAU

Show Extension Nodes (2) The extension nodes are what go down to the subscriber CP's to connect them to the switching network. There are a couple of different types of extension nodes. The largest of them is called the Large Extension Node or LEN. The LEN is a very large switchboard and can provide service to 176 subscribers. There is one LEN per division and it is normally found at the Division Rear complex where there are large number of subscribers. Since this is such a large switchboard it has two multi- channel radio links to node centers. Show LEN (3) This diagram shows the LEN config- uration. The LEN, like the node center switch, takes up two vans plus a management facility. It has a single LOS radio van which installs two links to different node centers. It can also provide a TACSAT interface and an interface with commercial circuits. Signal doctrine provides for the use of indigenous communi- cation assets in the theater of operations. If there are suitable phone circuits available, they can be accessed through the LEN.

Show Extenstion Nodes (4) There are two versions of the Small Extension Node (SEN). One of them supports 26 subscribers and the other one supports 41. Each of these has only a single radio link to a node center. Show SEN The SEN's are very simple switchboards and they only fill one shelter. The SEN has one LOS van and installs a single radio link to a node center. Again, notice TACSAT inter- face can be accomplished there also. Show SHF (5) Remember I said with the MSE equip- ment the radio vans could be removed from the CP site? This depicts how it is done. Normally the LOS radio van is connected to the SEN switchboard by a cable that is only 1/4 mile long. This cable can be replaced by a very low power and very directional SHF radio link if necessary. This allows a CP to be hidden in a very deep, concealed hole where there might not be anywhere the LOS van could establish its link to the node center. Given the 5 KM range of the SHF link, it would be hard for the CP to find a place where it could establish its radio link. Show RAU (6) The Radio Access Units are the things that let the Mobile Subscriber Radio Telephones (MSRT's) have access to the over all switching network. They work very much like the civilian relay stations for cellular telephones do. MSRTÆs are mounted in vehicles and they consist of a telephone connected to an FM radio. The phone call goes from the phone to the radio and is passed up to the RAU which is on a nearby hilltop. The RAU then passes the signal to a node center switch for further routing.

Each node center has a RAU with it on the hill top. These are called local Raus. You can see that if every node center has a RAU, the whole battlefield would be pretty well covered so that wherever you drove you would be able to use your MSRT. Show Remote RAU But since each RAU can only handle 8 telephone calls through it at once, there are places where we would have to put extra remote RAU's. Places where there are large population densities like large CPs and along Main Supply Routes. The RAUs which are put away from the node centers are called remote RAUs. They pass the phone calls to a node center through the same sort of LOS radio link that all of the SEN's use.

-Each RAU can process 8 calls at a time but each one can have up to 50 MSRTÆs affiliated with it. That means that it can have 50 subscribers in its active memory and will process their calls. The optimum number is 25 subscribers, however, it can handle 50 if necessary.

-The planning range for the radio telephone and RAU is only 15 km. This is a fairly small range for a modern FM radio but it is small for reason. The reason is the RAU emits a cons- tant marker beacon for the mobile radio telephones to lock in on for affiliation and call set up. Since the marker beacon would be a dead give away for a RAU the strength of the radio was limited to reduce its signature.

Student Check: Q: Where are the remote RAUÆs placed? A: Around population densities and MSR's

Show RAU Deployment -This slide shows that even with a 15 km planning radius, with 92 RAU's per corps the entire corps area is pretty well covered.

-Now, if you were driving down a highway at 50 MPH it would not take you long to get out of the area covered by any particular RAU. The automatic hand off feature refers to the fact that if you drive out of the range of one RAU, you will be automatically reaffiliated with the next RAU down the road. Show Automatic Handoff -As this truck moves down the highway it will leave the effective range of the first RAUs radio and he will be dropped by it. However, he has driven into the area covered by the second one and his radio telephone auto- matically reaffiliates with the new RAU. If he had been having a phone conversation when he was dropped by the first RAU, he would have lost his connection. But he would have dial tone return immediately upon the automatic reaffiliation and would just redial. Show Mobile Subscriber Connectivity This slide depicts how mobile subscribers can be connected via either a node center or a remote RAU. Show MSE Architecture (7) The subscribers in their CP's are down in the valleys hiding from the enemy and are connected to the switching network by one or two LOS radio links. There are RAU's at each of the node centers and there are remote RAU's wherever they need to be to support population densities. The remote RAU's are connected to the switching system by the same sort of LOS link as the extension switches. Show Flood Search (8) The flood search process is what allows you to keep the same number no matter where you go on the battlefield. The principle of flood search supports communications survivability. The flood search technique incorporates backward-routing. In backward- routing, the called party's switch initiates all routing. Show Search Phase The first phase in flood search is the search phase. The originating switch sends out messages to all switches connected to it. The search message continues to be sent until one switch acknowledges the called party is affiliated with that switch. Show Return Message The second phase is the return phase. In this phase the terminating switch sends a call back to the originating switch via the best path possible. Show End-Of-Routing-Phase The end-of-routing-phase is the third phase. This phase is initiated by the originating switch. An end-of-routing message is sent to all connected nodes so that switches not involved in the call can clear their routing registers of the call attempt. Show Call Complete Phase The last phase is the call complete phase. This phase is initiated by the terminating switch once the called party hangs up. Show Affiliation (8) Before you actually are able to use your telephone you have to affiliate it. Affiliation is a process by which you tell the node center switch that you are connected to the SEN and ready to receive and make phone calls, so the system can find you when someone dials your number. All you do is enter through your phone key pad the numbers 8R, your PIN number, and your phone number. This brings your subscriber data base profile into the node center switches active memory and you can be found. Show Disaffiliation (9) It is important you disaffiliate when you leave a site. To disaffiliate you enter in 8C, your PIN number, and your phone number. This tells the node center switch to take you out of active memory. If you donÆt do this and leave the site you will have left a hot quad on the J Box. Someone else who comes on site may connect their phone to that same quad and have immediate dial tone without affiliating. The problem is, that it is not their phone number and they will never get any of their calls. They will get your calls. Student Check: Q: What must you do with all of your phones before you leave site? A: Disaffiliate them.

Show CP Site (10) In this scene we can see that a CP tent has been set up and with it is a Small Extension Node switchboard and an LOS radio van. The phone is connected to a junction box by WF-16 4 wire commo wire. The J box is connected to the switchboard by a 26 pair cable. The switch is connected to the radio van by a PCM cable but if it was necessary, they could be connected by an SHF radio shot. If this were the case, the radio van could be 5 km away. The radio van has established a multichannel link with the node center way up on a mountain top somewhere. The HMMWV has an MSRT in it which talks through a RAU which is up on a hill somewhere within 15 km of the CP. Student Check: Q: What could you do if the SEN died? A: Use the MSRT

Show DNVT (11) This is a drawing of one of the basic MSE telephones. It is a Digital Nonsecure Voice Terminal (DNVT). Can only be used for secret level conversations. Show DSVT (12) This is the Digital Subscriber Voice Terminal (DSVT). It is the other basic MSE telephone and this one allows you to insert your own COMSEC key into it. You will remember the MSE system is encrypted to the secret level. If you need to talk to someone at the TS level you would only have to call them up, insert the TS variable into the phones and you are then encrypted at the TS level. Show FAX (13) This is the MSE digital facsimile. It is fairly primitive by modern commercial fax standards but it is very rugged. It has a one page memory so a document can be loaded into memory and then sent to the other machine in a burst transmission. This keeps long trans- misions from tying up phone lines.

Show Subscriber Connectivity w/J1077 (14) This chart shows how the subscriber would connect either a DSVT or DNVT to a J- 1077. It is the user's responsibility to connect the telephones or other device to the J-1077. Show MSRT (15) This diagram shows how MSRT's are installed in HMMWV's. The phone is a DSVT and is mounted between the passenger and driver. The radio is behind the passenger and is connected to the phone by a cable.

3. CONCLUSION

a. Review of Main Points: During this class I have discussed:

-The ATCCS communications architecture

-MSE as the ArmyÆs Area Common User System at corps and below.

b. Questions or Comments?

c. Tie-in: This class should have made it clear that communications on the modern battlefield are varied and complex. As an MI officer you will have to be able to use a number of different means in order to communicate both within the MI community and with other Army units. Your effectiveness will depend upon your mastery of the communications systems available to you.