COMMUNICATIONS I: WAR ON THE AIR WAVES
Communication is the core of humanity's efforts to accomplish any and all tasks at are too great for one person to do alone. Nowhere is this truer than in warfare. Entire armies have, over the course of history, been routed by inferior forces with superior communication. Unsurprisingly, that makes radio communication just as important in BattleTech's far-future setting as it is today.
BattleTech's rules for wireless communication are, in many respects, very simple. The stats of radio communication equipment have no defined rules dictating how they are affected by various atmospheric conditions; those and many other details are left entirely to the discretion of the gamemaster. For this reason, this article will also reference many real-life principles of radio communication. Note, however, that this will
not be a comprehensive lesson on the physics or protocol of radios, but rather a summary of various aspects dictating the use of radio communication as they exist in BattleTech, with additional information that will be helpful for players and gamemasters if they would like to integrate more involved radio communications into their games.
BASIC TERMINOLOGYNote that this article defines these terms as they relate to radio communications. They may also have similar or separate definitions across the rest of the electromagnetic spectrum and beyond.
Radio: Radio is the use of electromagnetic waves with a wavelength between 0 hertz and 3 terahertz, used primarily for communication.
Transmit/Receive: To transmit (abbreviated as "TX" or "Tx") is to emit a radio wave, intentionally or otherwise. To receive (abbreviated as "RX" or "Rx") is to receive that wave.
Power/Sensitivity: Transmission power is the strength of the transmission, and serves as one of the main factor in a radio's effective range. Sensitivity refers to the ability for a radio to detect and receive radio transmissions.
Propagation/Attenuation: Radio propagation is the ability for radio waves to travel over long distances, while attenuation is the rate at which those signals are degraded by a variety of factors.
THE BASICS OF RADIO COMMUNICATIONOn the face of it, radio communication seems fairly simple. As long as you're within range, just hit the transmit button and talk to your buddy a few kilometers away, right? Well, there are a few other factors to consider.
One that is often easy to forget is that the effective range given for a radio is only for
transmitting. This means that even a basic personal communicator with a small range can still receive one-way communications from a much more powerful radio that may be quite far away. This, in theory, allows commanders to quickly issue orders (for example a general cease-fire or surrender) to all of their troops, even those only carrying short-range radios meant for intra-squad communication.
Another matter often overlooked is the difference between half-duplex and full-duplex communications. Most of us will be familiar with full-duplex radio communication thanks to our phones, which connect to established network infrastructure to send and receive transmissions at the same time. Outside of rear-echelon trunk networks, however, most military and hobbyist radio communications are half-duplex. This means that a radio cannot receive and transmit at the same time, and usually also prevents radios from receiving more than one transmission at a time. This requires increased radio discipline (keeping a radio transmitting as a "hot mic" to jam a net is a common mistake with inexperienced radio operators), but allows users to be far less reliant on expensive and cumbersome network infrastructure. It is unknown if the combat-net radio networks in BattleTech still rely primarily on half-duplex radios, but if you're a gamemaster looking for additional opportunities to test your players' ability to stay cool in combat, it can be good to keep in mind.
There's also the matter of radio protocol. While BattleTech usually uses NATO-inspired terminologies and protocols, each nation, and indeed each force will have its own radio protocols to some extent. Some will make extensive use of brevity codes and jargon, while others may be more literal and informal. One common feature are the words "over", which is used to signal the end of a message with an expected reply, and "out", which is used to signal the end of a message with no expected reply. As with the matter of duplexing, gamemasters should consider what sort of radio protocols different forces may use, and whether or not the players should be expected to follow those protocols.
Sometimes it's impossible for an element to maintain communication with their chain of command on their own. Combat in dense or hilly areas can quickly degrade radio communications. The most common solution to this is to use aircraft as communication relays. Another solution, where available, is to bounce a transmission off of a friendly communication satellite. In a few cases, it may be possible to use a local relay hooked into a wired connection, though this is almost always limited to defensive operations as it requires that the players already have in-depth infrastructure in place.
THE RADIOS OF BATTLETECHSeveral different wireless communications systems in BattleTech that are stated or implied to use radio waves listed in
A Time of War on page 301. These make up the majority of radio systems in BattleTech.
Communications Headset
This small headset has a miniscule 100-meter transmission range, but is seldom expected to work on its own. Instead, these headsets are most often connected to a local relay, allowing the wearer to stay in communication without needing a wired connection or heavy radio so long as they stay within range of the transmitter. Furthermore, their short range is irrelevant if the user needs only listen for a signal transmitted by another source. Furthermore, these headsets consume power at an incredibly low rate; they can be left on for over three months straight when powered by just a single civilian micro power pack. | Civilian Communicator
Essentially a cell phone, Civilian Communicators have a more respectable range of 10 kilometers, albeit only with line-of-sight on the receiver. Like the communications headset, the draw is the low cost and small power draw, as well as their ubiquity. Civilian Communicators also come in micro-form, with a fifth of the range and almost four times the cost; Civilian Microcommunicators do, however, have the advantage of being small and weighing only a fraction of their larger brethren. |
Long-Range Communications Kit
A longer-range communications kit, this civilian kit enjoys the longest effective range of any radio that can be easily carried by the average person. Though it's less weight- and power-efficient than most military communicators, this gives it a niche to fill in situations where ground troops can't bounce their communications off of a nearby friendly vehicle. Furthermore, it is one of only a few non-vehicular radios capable of establishing a connection to a satellite in orbit, and the only non-vehicular radio with this functionality that is not associated with ComStar. | Intercom-Link
The Intercom-Link serves much the same purpose as the Communications Headset, albeit even more extreme. While the user is wirelessly tethered to within less than a dozen meters of the network hub, the link allows each member of the very-short-range network to hear each other even over loud noises. This communicator is favored by vehicle crews (particularly for noisy vehicles, such as helicopters) and industrial workers. |
Satnav Receiver
The Satnav Receiver is, in essence, a GPS, using radio signals to communicate with a satellite network for accurate positioning information. Though it requires existing satellite infrastructure, a Satnav Receiver paired with a map and compass virtually guarantees that even the most junior of lieutenants can find their way through any environment. | Civilian Relays & Hubs
Due to the short range of most civilian communicators, relays are essential to keeping traffic running. These come in small and large varieties, extending the range of nearby civilian communications. Up to 30 of these relays may be connected to a civilian communication hub, providing superior coverage and redundancy within a network. |
Military Communicator
Though the Military Communicator shares its range with standard Civilian Communicators at a higher price tag and power usage, it is less affected by obstacles blocking line of sight, and naturally includes more encryption options. These are standard-issue for most militaries in the Inner Sphere and Clans, so much so that some nations' armor kits integrate them into the helmet. Like their civilian version, Military Microcommunicators provide a smaller, more discreet option, though they are much lighter and have over double the range of their civilian counterpart. | Field Communicator
A longer-range communicator meant for field commanders, RTOs, and the like. With a 25 kilometer transmission range, field communicators can facilitate communications between firebases and patrols, as well as allowing infantry to coordinate with local support assets like air support and artillery. |
Advanced Field Communication Kit
ComStar's special communication suite, the Advanced Field Communication Kit is too heavy for the average man to carry around the battlefield alone, and requires a crew of 5 for maximum effectiveness. In exchange, the kit provides unparalleled transmission capability, matching forty tons of vehicular Communications Equipment in range and enabling contact with satellites. Though cumbersome for infantry, the 100-kilogram package can easly be affixed to nearly any vehicle, affording the officers of Com Guard divisions the ability to turn almost anything into a mobile command center capable of coordinating divisions and even armies. | Subvocal Microcommunicator
Able to amplify even the quietist whispers when properly worn, these communicators allow a user to speak over the radio without much fear of eavesdroppers. The method of speaking is, however, not the most intuitive, meaning users must already have some experience using conventional communications. A favorite among agents deep within enemy territory, disguised operatives are able to report their findings in real-time without blowing their cover, while hidden infiltration teams can coordinate their actions despite being no louder than the wind. |
Military Relays & Hubs
Like its civilian counterparts, the Military Relay Antenna acts as a transmitter and repeater for local military radio traffic, as well as the main communication system for military vehicles. Though its range is not terribly impressive, one is sufficient to facilitate communication across large base complexes, and multiple can be daisy-chained together to carry messages between bases, usually as a temporary measure until a wired trunk network is established. Military Communication Hubs, also known in Total Warfare and its supplements as Communications Equipment, is unique for its ability to expand itself with additional modules. While a 1-ton Military Communication Hub can transmit a signal up to 25 kilometers away, additional 1-ton-lots can add extra power, up to a maximum of 15 tons. | Communications Implants
Characters who wish to have a deeply-concealed or practically un-removable communications system can have one cybernetically implanted in them. Though versatile, these communications implants are limited to a very short range. The Word of Blake, however, devised a series of Boosted Communications Implants for their Manei Domini cyborg soldier which increased the effective range by a factor of 10, giving them a 1-kilometer range more useful on the battlefield. |
It's worth noting that most military vehicles already come with some Communications Equipment pre-installed. 'Mechs (including ProtoMechs), combat vehicles, fighters, and satellites come with 1-ton, while small craft and larger receive more. In addition, PA(L) suits carry communication suites equivalent to a Military Communicator, with Battle Armor carrying the equivalent of a Field Communicator.
SIGNAL ATTENUATIONThere are a number of conditions that can inhibit the ability for a radio signal to propagate and reach it's intended receiver. Below are the main aspects responsible for attenuating radio signals (though some other conditions may, in rare circumstances, cause a signal to become attenuated at an increased or reduced rate).
AtmosphereThe main reason that radios have a limited range, even within line of sight, is the atmosphere. Much like how light refracts to make distant objects look slightly blue, radio signals are degraded by extended travel through air. As atmospheric pressure in BattleTech is helpfully expressed in bars (where 1 bar is equal to roughly the average pressure at Earth's sea level) Gamemasters can divide the given range for each piece of communication equipment by the planet's pressure as a simplified shorthand for the increased or decreased rate of propagation on planets with especially thin or dense atmospheres.
Atmospheric attenuation is also affected by weather conditions. Generally speaking, harsh weather conditions further reduce the effective range of a radio transmission. It's also worth noting that weather patterns often bring with them changes in atmospheric pressure, which may mitigate or accentuate the reductive effect weather can have on radio communications.
The ionosphere can also play a major part in atmospheric communications. This atmospheric layer, overlapping part of the mesosphere and thermosphere, can "bounce" radio communications within the atmosphere, allowing for increased range without any need for line of sight if the conditions are right. This does, however, present some degree of added difficulty when transmitting into space, particularly for equipment not designed with transatmospheric communication in mind. Gamemasters may choose to further attenuate a radio signal that passes through the space/atmosphere interface row of the high-altitude map to reflect this.
A radio used in a vacuum has an effectively limitless range within line of sight (though in the wide reaches of space, one must account for the speed of light to account for the significant delays that may be present with stellar radio communication).
ObstaclesRadios operate best when they have a clear line of sight. However, in most practical cases, there is likely to be some obstacle between the transmitter and receiver which may attenuate or completely block a transmission. While thin stucco and plaster is unlikely to meaningfully block powerful radio signals, dense metals and thick concrete can quickly render radio communications unreliable at best, and unusable at worst. Gamemasters will have to make individual judgement calls on how different obstacles will affect transmissions.
One notable obstacle is water. Radio waves propagate extremely poorly in water, meaning that submersible vessels must surface to send or receive radio signals. It is for this reason that most underwater fortresses feature subterranean cable networks leading to aboveground and/or buoy-mounted radio antennas. Cut off these connections, and any underwater units or positions without hard-wired connections to other installations will be totally isolated (though submarines often feature alternative underwater communication methods to contact one another, albeit with shorter range or increased lag).
Interference/ECMEach radio is not alone, but takes up one band on the electromagnetic spectrum shared by almost all other wireless devices. The radiological effects of nuclear materials, bandwidth congestion from a busy area with too many devices attempting to use the same frequency bands, or deliberate jamming by an enemy ECM system can all make receiving transmissions difficult or even impossible. It should be noted that this interference, unlike most others, does
not inhibit a radio's ability to transmit, only receive. This means that jammed units can still transmit freely, able to warn approaching forces of any known or suspected threats. Reducing two-way communication to one-way is, however, often enough to break or at least strongly inhibit a team's cohesion.
Equipment DegradationA poorly cared-for radio running on near-depleted batteries is only going to have a fraction of the transmission range and will likely have much more trouble receiving signals compared to a well-maintained radio with ample power. Though almost all military and survival radios, along with many hobbyist radios, will be designed with durability in mind, even the most rugged radio will degrade with time. If players are part of a force that must make do with sub-par equipment, or are playing a campaign with the equipment maintenance rules from
A Time of War Companion in effect, damaged or degraded radios will likely have significantly reduced range, and in extreme cases may even experience reduced receiver sensitivity.
ELECTRONIC SUPPORT MEASURESMost radios are omnidirectional, meaning that they don't limit their transmission to a single direction. This opens up the possibility that players (or their opponents) may detect, intercept, and analyze enemy transmissions. Detection can usually be accomplished with appropriate gear and a Communications/Conventional check of moderate difficulty (easier if the character in question already knows the frequency bands most commonly used by the enemy). Once a signal has been detected, interception merely entails recording (or, if the signal is unencrypted, simply listening to) to the transmission. Furthermore, if the transmission is detected by three or more antennas with synchronized clocks, the transmitter's location may be triangulated with an appropriate skill or INT attribute check. Finally, analysis on intercepted transmissions, often requiring a cryptography skill check, can provide key information on the enemy, as can an analysis of enemy movements by triangulating their radio signals.
Detecting radio signals is also a key part of locating ships in space. Any ships emitting radio signals in space may be detected by civilian vessels within 500,000 kilometers, while military ships can detect these from as far as 10,000,000 kilometers out. For this reason, it is essential that any ships intending to act discreetly within a defended solar system should spend as much time as possible "going dark". Maintaining stealth in the openness of space is already a difficult prospect, but perhaps the easiest way to ruin any sense of surprise may be a single errant broadcast. This is accentuated further by Naval Comm Scanner Suites, which specifically monitor the surrounding space very carefully to detect emissions from up to a fifth of an astronomical unit away.
USES FOR RADIOS IN MATCHES AND CAMPAIGNSNow, knowing this is all well and good, but how should a gamemaster apply it? Aside from what has been given in bespoke rules, creative gamemasters can create a number of interesting and tense scenarios by cutting off communication for all but the more prepared parties. With some exceptions, an armed force can only effectively project force as far as they are able to extend their lines of communications. Thus, if you're worried about players blitzing the final boss of your campaign arc by making a break straight for the main enemy headquarters, ignoring any other enemy installations, it may be prudent to ensure that the final encounter is set to take place over 25 kilometers away from the players' base camp. This discourages players from over-extending their forces, as after the 25-kilometer mark the players will be unable to call for aid if they have not taken the time to set up or capture communication relays along the way (unless of course a player chooses to augment their 'Mech with an extra ton of Communications Equipment, in which case they ought to be rewarded with the chance to make use of it). Communications also have a strong impact on players' ability to call fire support. An infantry company with no long-range radio operator may find themselves high-and-dry of artillery or air support when they need it most, despite having Long Tom batteries well within firing range and fighters on the tarmac just waiting for the go-ahead. This may encourage players to try building characters with a more diverse set of skills and equipment beyond what is needed for a small party to stay in touch.
ECM also becomes much more important. The oft-neglected
Raven RVN-1X, derided as being an ECM-oriented 'Mech in an era where ECM has very little use, can become much more potent when using
A Time of War's rules that allow ECM to block communications. Whether it's a 'Mech who's player is forced to wear earbuds with music while the rest of their lancemates discuss tactics for the turn, a platoon of infantry unable to receive warnings from reconnaissance aircraft, or a company of tanks left unaware that the rest of their forces are retreating, using ECM to cut units and players out of the loop can be a powerful tactic. The same holds true for players in charge of an irregular force fighting against a superior conventional force; it may be worth taking the penalties for fighting in a thunderstorm or some planetary electromagnetic phenomenon if it means the enemy is going to have a hard time calling in a fire mission or reinforcements.
As most of these rules are taken from
A Time of War, which focuses heavily on immersion and details, I'd recommend that gamemasters don't get too uptight about the specifics of radio usage in campaigns run through
MechWarrior Destiny.
Destiny's more free-form, fantastical tone and mechanics are likely to simply get bogged down into reductive tedium if the above principles and recommendations are followed—though it may still be worth keeping in mind that communicators don't have infinite range. Instead, gamemasters should handle issues with reception based on what best fits the flow of the scene, and should only concern themselves with radio mechanics if a player wishes to play as a radio specialist (such as a ship's communications officer).
SUMMARYHopefully, you've come out of this thinking of ways to integrate radios more completely into your matches and campaigns. I personally find electromagnetic physics and combined-arms communication to be fascinating topics, though I tried not to get away from myself and into too many overly-complicated details or too much jargon. But, as communication is the life blood of every military, I think it's an incredibly important factor that frankly should get a lot more attention by authors and fans.
Anyways, thank you dearly for your time and attention. Check back every now and then for Communications II: Interstellar Express, coming Eventually™!
BIBLIOGRAPHYA Time of War, Catalyst Game Labs
A Time of War Companion, Catalyst Game Labs
Electronic Warfare for the Digitized Battlefield, Artech House
Strategic Operations, Catalyst Game Labs
Tactical Operations: Advanced Rules, Catalyst Game Labs
TechManual, Catalyst Game Labs
