The development of Soldier Modernization Programs (SMP) across NATO and other countries poses challenges — not only through the extension of voice and data communications down to each infantryman, but the parallel need to define the level of security required to protect the information sent.
Communications security for individual soldiers cannot be addressed in a vacuum. The level of security needed has consequences at all levels of design. At a systems level it is important in terms of power and weight; doctrinally in terms of what level of interoperability is desired and at which echelon of command; procedurally in terms of the physical security of the device; and programmatically in terms of the individual cost which is multiplied by the tens of thousands of systems required.
Norway's NORMANS is one of several soldier communications programs proeeding internationally. Norwegian MoD photo
“On the one hand we all want secure communications throughout, but in practical and operational ways it makes things very difficult,” stated Lieutenant Colonel Koos Meijer (Ret.), the recently retired former head of the Netherlands D2S2 SMP and Deputy Chairman, Topical Group 1 Soldier Systems Interoperability, NATO Army Armaments Group, responsible for the Alliance’s work on the area and now head of the Elkoom Consultancy (Nunspeet, The Netherlands), outlining the balance that must be found between competing requirements.
Technically ‘Doable,’ Practically Not
Two factors drive security classification: the status of the network that is being accessed and the classification of equipment that each soldier is cleared to carry. Today’s individual Personal Role Radios (PRR) — a relatively new class of radio — are almost exclusively voice with limited security and range. As soldier systems begin to gain more intelligence and data, particularly location and basic messaging, then the information becomes more important and requires greater security. As a consequence, the complexity of the PRR-type radios and their cost will rise. However, for horizontal communications such at the lowest level, according to Richard Ransford, Systems Engineering Manager, Vehicle and Soldier Systems at Thales UK (Weybridge UK), “you do not need to go up to a JTRS-style radio for communications at the section level.”
For vertical communications, however, when sending aggregated section data upwards from platoon and company level or when connecting to larger secure networks to access battlefield CIS, the radio will need to have encryption and protection which is compatible with these larger networks. Discussions are underway throughout NATO on determining the level of encryption necessary for this information to leave the network to be then passed via the section leader’s node to individual section members and the associated security needed to make this possible.
The H4855 Personal Role Radio began life as a voice solution using spread spectrum technology rather than encryption for security. As it develops its inherent data capability this is being increased by the addition of AES encryption for the SMP role. Selenia Communications photo.
The security models that are implemented for high-level US Type 1 or UK High Grade Product hand-held and manpack Combat Net Radios (CNR) are inappropriate for such low level communications. “At the moment if I give a soldier a radio with a fully encrypted system, he has to be more secure with that radio than he is with his personal weapon. That is the problem,” explained Colonel Meijer.
Further issues arise with the use of encryption keys. Colonel Meijer explained that although over the air solutions solve some of the encryption key issues, the associated physical security imposes unwanted rigidity on any solution and its implementation: “Each soldier has to be very secure. He has to carry the radio at all times. In order to operate crypto, you need crypto keys and the question arises as to who ‘owns’ these keys and where they are. In operations, unfortunately, you can guarantee they will not be where you need them to be when a change of crypto is required. The issue for SMPs now is whether they can solve those problems. I believe we can, but it will take time and mean the systems will be less flexible than the users believe they need.” Col. Meijer noted that the addition of high level crypto also adds to the radio’s weight and power consumption and at the same time decreases the bandwidth throughput possible in protected ECCM modes. This requires the radio to spend more time transmitting and thus drains the batteries more frequently, leading to the need for more batteries or more frequent recharge. All this has the effect of placing greater burdens on the individual soldiers and impacting on their ability to fight.
Security Today
There are no easy answers and although prototype and pre-production SMP solutions exist and have seen some limited fielding, no absolute solutions to the problem have been produced. The most successful of the current radios is the Selenia Communications (Chelmsford, UK) H4855 Personal Role Radio. Over 100,000 sets have been sold to customers including the UK, USMC and USAF. There are 24 countries in total using the sets, with national differences limited to differences in connectors for headsets or the color of the radios.
The PRR has no encryption. Despite this, effective security has been achieved via several other approaches giving a layered solution that also points to methods that may be adopted by others in the near future. Firstly, the information sent in voice only is transient, according to Alan Heritage, Business Manager at Selenia Communications, offering little or no tactical benefit to an eavesdropping enemy. Secondly, the range is limited — 500 m in clear space but only 150 m in urban terrain or multi-story buildings — making it difficult to detect from a distance. This low range is coupled with low output, resulting in each PRR needing just two primary cell AA batteries for 24 hours of operation. Thirdly, the solution uses spread spectrum technology, which enables the transmission of wideband, noise-like signals which are widely used in the civil sector. These signals are hard to detect, intercept or demodulate and are harder to jam than their narrowband counterparts. These factors result in an effectively secure radio at reduced cost, so much so that the British Army acquired 45,000 items in 2001 in a contract worth approximately $36.5 M.
When discussing which programs are exploring this technology, Richard Ransford stated, “Spread spectrum technology allows you to disappear into the background noise and it lends itself very nicely to the ‘front end’ because the enemy cannot see you coming. It is very difficult to detect in the particular areas of the spectrum used to find information and so it is fairly difficult to spot. It is a good way forward.”
Selenia Communications is now preparing a longer-range data capable version of the PRR to meet the requirement of SMP. This will be equipped with commercial 128-bit AES encryption with longer range and with moderate data throughput sufficient for section level situational awareness and low power consumption.
Land Warrior is addressing the issue of soldier security balancing the need to provide soldiers with a usable solution for mass use in the field that is certified to take information generated by higher-level systems. US DoD photo
Other solutions competing in this nascent SMP oriented market are Thales’ Soldier Advanced Radio (already in service with the Bundeswehr and deployed unencrypted) and the Tadiran Communications (Holon, Israel) PNR-500, which has adopted similar approaches. However, a key difference is the auto-synchronization feature of the PNR-500, which replaces the need for a nominated master station in ‘PRR’ networks.
Tadiran Communications is also allowing security options in its CNR range to enable greater bandwidth. The new CNR 9000 High Data Rate radio enables the user to switch between a standard 64 kbps CNR capability using an encrypted frequency hopping waveform, to a 115 kbps encrypted rate over a 25 kHz narrow-band VHF/FM channel, thus better enabling ISR throughput at the manpack level for SMPs and others.
The US answer to the problems of security and low-level communications has been to a large extent the Soldier Radio Waveform (SRW) being developed by DARPA and ITT under the Soldier Level Integrated Communications Environment program. This will be the dominant waveform for dismounted soldiers equipped with JTRS Cluster 5 radios. The SRW is designed from scratch to be a power efficient and jam-resistant, agile network waveform providing both communications and geo-location information within difficult terrain. Equipped with four distinct nodes, data rates differ according to mode and circumstance. In Combat Communication Mode, burst rates at a 1.2 MHz allocation begin at 900 kbps rising to 2.4 Mbps, while at 4 MHz, these rise to 8 Mbps. In EW and LPD/LPI mode these are much less, ranging from 3.9 kbps to 187.5 kbps and 3.9 kbps to 46.9 kbps at 1.2 MHz, respectively. According to the prevailing security circumstance the SRW will adapt to deliver the best balance of bandwidth and security to deal with either a future peer competitor or urban insurgent.
While the SRW will provide some security, encryption will be determined by other means. Differing levels of security are manifest in the Land Warrior designs. The Cluster 5 ‘Leader’ and ‘Soldier’ embedded radios operate the same five waveforms, but while the ‘soldier radio’ will support National Institute of Standards security, the Leader radio will have higher National Security Agency encryption.
The Embedded SFF variants within JTRS Cluster 5 will use both NSA and lower grade NIST security depending on the radio varient's role in Land Warrior. General Dynamics photo
Unique amongst SMPs, the US is providing all its Land Warrior ensembles with SATCOM, illustrating the ‘foxhole to Pentagon’ reach of the Global Information Grid and associated security requirements. All the Small Form Factor embedded communications — SFF B and C — for Land Warrior will support Mobile User Objective System UHF SATCOM when that comes on-line in 2010. In the meantime they will be able to operate with the 181-3 DAMA SATCOM. The hand-held JTRS Cluster 5 radios have the Objective requirement for Mobile Satellite Services. With access to this Beyond Line Of Sight capability, low-level security is simply not an option.
Bluetooth on the Battlefield
Bluetooth solutions on an individual soldier level are being explored, not to link soldiers together but as a means to interconnect disparate pieces of equipment around the body. For this technology the term ‘secure’ not only means protected against eavesdropping or jamming but able to function in all environmental circumstances.
Power is a key limiting factor for wireless — while voice and data can be sent over the air, power cannot. It is not, however, the only factor. “There are some big health question marks around the effect of having wireless connections so close to the body and these are being studied,” stated Colonel Meijer.
A wireless solution would be the optimum solution. Each cable that can be eliminated enables less restricted movement. Issues remain, however, on whether multiple wireless connections could cause interference and whether environmental conditions will impact performance. Independent of whether Bluetooth will work is the issue of the power consumption and power distribution. Power cannot be transferred to a device other than by physical connection. If a connection between a torso-mounted central power unit and the device itself, such as a hand-held computer, has to be wired anyway, the benefits of having a wireless system to exchange information round the soldier are cancelled out. If the external power source is eliminated then instead a battery has to be installed on the device. Such a policy writ large would see multiple battery types, one for each type of device, each requiring daily recharging, multiplied by several thousand soldiers — this obviously poses massive logistic challenges. That is not to say such devices are not being fielded and tested. The Dutch have examined a Bluetooth connection to link a wristwatch to a wider communication system. The watch vibrated in different ways to communicate high importance messages that needed to be widely disseminated such as incoming artillery or NBC attack. Germany’s IdZ program has fielded a Bluetooth solution to link its NavIPad situation awareness display to the body mounted communications package. Sagem, leading France’s FELIN program, has established a parallel solution to link the FAMAS assault rifle to body worn systems. While being carried, a wired connector links weapon and power sources enabling the central battery to power the system and charge the on board battery. In combat this connection can be pulled out and the battery on the weapon itself powers its functionality until reconnection. Looking further a field there are other commercial solutions. Tadiran Communications ‘Radioos 100’ allows multiple users to access a single CNR via a Bluetooth connection over 20 m via a headset.
Initially, Bluetooth applications appear to be limited. Steve Turner, VP Vehicle and Soldier Systems, Thales UK, gave his opinion on UK adoption of these systems. “During the FIST functionality trials in 2004, we leaned more toward wired rather than wireless. We might have a Bluetooth node on FIST, but the current configuration for what looks to be the in service capability for FIST looks like being wired gives us a better chance of managing the overall power budget.”
Interoperability
The security challenges of sharing information between section leaders and their units pale into insignificance compared to the security concerns for international interoperability. The interoperability picture is mixed and is currently quite limited. A desire to extend this interoperability imposes further restrictions. Interoperability amongst national CNRs is limited to either fixed frequency and unencrypted or in some cases the addition of an external crypto such as that demonstrated with Bowman VHF ADR+ plus the US KY99 module which can be achieved for a limited number of radios.
Further and deeper US-UK interoperability via Bowman-JTRS is now being explored. This will see roughly half of the UK’s Bowman VHF modes having encryption and ECCM protocols embedded in a US JTRS radio. This process will start with Cluster 1 thanks to its use of the Sierra II software defined encryption chip. The UK security protocols embedded in the Cluster 1 radio will enable US radios to join UK networks rather than vice versa in a warfighting environment.
When fully implemented, communications routed from a British soldier equipped with today’s PRR or the FIST communications solution would be able, via a Bowman VHF radio, to communicate with dismounted JTRS forces when Cluster 5 becomes available. Commonality is one way to go at this level for interoperability. The USMC in Iraq selected the PRR, as it would provide immediately interoperability with British and other users. Each PRR supports 16 groups of 16-networked users — 256 difference combinations — deliberately designed to provide a company-sized formation PRR communications system without interference. As there is no encryption of frequency hopping in each radio, a British, US Marine, Kuwaiti or Saudi soldier could form a network or join another simply by switching to the correct grouping.
Again, however, doctrinal and other issues nix technical possibilities. The UK’s FIST studies concluded that interoperability is best achieved at the company level. According to Steve Turner, “There are doctrinal issues to making interoperability possible at lower levels. From a command structure perspective you do not want a section leader doing something with another section leader without going through the chain of command. The company level is where the exchange of information between nations or different companies should take place.”
The ability to deliver security is not just a matter of technical solutions. It impacts on a wide range of other factors in SMP design and is unique to the dismounted soldier. Compromise and cooperation are not normally terms associated with information security but countries are increasingly turning to non-traditional but effective solutions to equip SMPs.
