The RC10 has an embedded STANAG 5066 ARQ stack and the STANAG 5066 embedded clients are normally required by most users. The RC10 complies with all the mandatory requirements of STANAG 5066 Edition 4. The RC10 is intended to work in conjunction with the RM10 Wideband SDM & ALE for secure HF data communications solutions with an external cryptographic unit. The RM10 is a rack-mount modem unit with a software option for embedded wideband HF data modem waveforms complying with MIL-STD-188-110D and STANAG 5069 (Block 3) and the Wideband ALE (WALE) controller functions, specified in MIL-STD-188-141D. The RM10 provides raw over-the-air (OTA) data speeds of up to 120 000 bps on surface wave and beyond-line-of-sight (BLOS) HF communication links. The RC10 can connect directly to external email servers and Military Message Handling Systems (MMHS). A notable client supported by the RC10 is the IP client for IP-over-HF applications.

The RC10 platform also has embedded software for the Mobile Ad-Hoc Relay Line-of-Sight Networking (MARLIN) protocol based on the NATO ACompP-4691/STANAG 4691 Annex A (Version 1) specification. The RC10 is intended to work in conjunction with the RM10 Wideband SDM & ALE for secure V/UHF IP-based data communications solutions with an external cryptographic unit. The RM10 is a rack-mount modem unit with a software option for embedded V/UHF data modem waveforms complying with STANAG 4691 Annex B (20/25 kHz) providing raw data speeds of up to 96000 bps on UHF line-of-sight (LOS) communications links. The RC10/RM10 combination, when coupled to VHF or UHF wideband radios, provides a versatile IP-based data communication system. The RC10’s embedded MARLIN STANAG 4691 networking controller supports a multi-hop relay function that will effectively transform a LOS radio system into extended line-of-sight (ELOS).

The RC10 is suitable for installation on naval and maritime below-deck platforms (surface, sub-surface and air) due to its compact form factor and environmental specifications, especially the wide temperature range. The RC10 has added capabilities to allow it to also operate in high-power NATO shore stations e.g., those with broadcast and ship-shore (BRASS) including BRASS Initial Core Capability (BICC) and BRASS IP Enhanced System (BRIPES), BRASS Enhancements 1 Technical Architecture (BRE1TA) and BRASS Enhancements 2 Technical Architecture (BRE2TA) configurations. The RC10 can operate in either fixed-frequency or multi-frequency networks, and it provides interoperability with other STANAG 5066 products such as RC66, BFEM66, 4KMA and RIFAN.

The RC10 STANAG 5066 ARQ protocol stack supports the following operational modes: ARQ, non-ARQ (broadcast) as well as EMCON (emission control). The RC10 supports the Subnetwork Interface Sublayer (SIS) interface protocol. This SIS interface enables multiple applications to send and receive data simultaneously. The data associated with an application has a priority. The STANAG 5066 ARQ protocol stack supports multiple applications by multiplexing and prioritising data sent over the air ensuring that higher precedence data will be sent first. The STANAG 5066 stack can simultaneously communicate in both directions on a given communications link.

The RC10 implements advanced collision avoidance and recovery as well as a listen-before-transmit function to improve overall network throughput. It can also automatically adjust the transmitter data rate by using the built-in DRC functionality, provided modem control is available.

The STANAG 5066 Edition 4, referred to as wideband ARQ (WB-ARQ), addresses data operation up to a maximum data rate of 240 kbps. The RC10 provides data operation from 75 bps up to a maximum of 120 kbps. The latter agrees with a wideband HF radio system offering a maximum bandwidth of 24 kHz.

STANAG 5066 Edition 4 Annexes A, B, C, D, F and S are marked as mandatory requirements. The RC10 complies with the mandatory requirements of Annexes A to F and S, and a subset of the optional requirements of these annexes. STANAG 5066 Edition 4 Annexes E, G, H, I and M have been removed and are therefore not applicable.

STANAG 5066 Edition 4 Annexes J, K and L address the Media Access Control (MAC) capabilities. The RC10 complies with the requirements of Annexes J and K. Annex L, addressing the WTRP function has been changed completely in Edition 4 and interoperability with the Edition 3 implementation is not achievable. RapidM has plans to update the current RC10 Edition 3-based WTRP implementation to comply with the Edition 4 specification in future.

STANAG 5066 Edition 4 further introduced Annexes R and T specifying the Routing and TRANSEC crypto sublayers as optional features. RapidM has plans to implement these annexes in future.

STANAG 5066 Edition 4 retained most of the clients specified in Edition 3 as part of Annex F. In Edition 4 these clients have been moved into their separate annexes. There are no new clients defined in Edition 4, but the S4406 Annex E and IP clients have been updated. Some clients have been removed from the Edition 4 specification.

The RC10 supports networks consisting of both STANAG 5066 Edition 3 and Edition 4 nodes concurrently. As part of the RC10 addressing configuration, it is specified on a per-node-basis whether the node is Edition 3 or Edition 4 capable. The default configuration assumes an Edition 3 capability when communicating with nodes not yet added to the routing table.

When the RC10 is configured for Edition 4, it will only be able to concurrently communicate with nodes being Edition 3 or Edition 4 capable. As part of the link request, the Edition 4 node determines whether a remote node is Edition 4 capable or not. If it is determined that the remote node is not Edition 4 capable, then all ensuing STANAG 5066 data exchanges will be completed using Edition 3 functionality thus without the use of any features associated exclusively with Edition 4.

Alternatively, if via the STANAG 5066 link request, it is determined that the remote node is indeed Edition 4 capable, then all ensuing STANAG 5066 data exchanges can make use of the Edition 4 functionality.

When the RC10 is configured for Edition 3 only, it will only be able to communicate using Edition 3 features. Note that no Edition 4 features will be used if communicating with Edition 3 nodes.

The STANAG 5066 Edition 3, referred to as narrowband ARQ (NB-ARQ), addresses data operation up to a maximum data rate of 9.6 kbps in 3 kHz and 19.2 kbps in 2 × 3 kHz (ISB).

STANAG 5066 Edition 3 Annexes A, B, C and D are marked as mandatory annexes. The RC10 complies with these requirements. STANAG 5066 Edition 3 Annexes E, G, H and M contain important implementation guidelines, whilst Annex N is a placeholder to provide TDMA operation in future. The latter annexe is empty and therefore not applicable.

STANAG 5066 Edition 3 Annexes J, K and L address the Media Access Control (MAC) capabilities. The RC10 complies with the requirements of Annexes J, K and L.

The applicable data clients are specified in Edition 3 as part of Annex F.

The RC10 offers as a software option, the standards-based MARLIN controller as specified in the NATO STANAG 4691 Annex A, used for fixed frequency ad-hoc V/UHF networks. This controller supports the data modem waveforms as specified in the NATO STANAG 4691 Annex B with supported data rates from 12 800 bps to 96 000 bps. The MARLIN controller is based on the use of a synchronous Time Division Media Access (TDMA) scheme called Distributed Slot Reservation Media Access (DSRMA). Each MARLIN node maintains a fixed allocation of time slots in each frame. The number of allocated slots per node is automatically adjusted based on data demands, using the dynamic bandwidth allocation mechanism.

The RC10’s STANAG 4691 (Annex A) controller is used in conjunction with the RM10’s STANAG 4691 Annex B (20 / 24 kHz) modem.

The RC10 unit has a bit-exact synchronous DCE interface compliant with the EIA 530A standard. The interface is intended to connect to the RED side of standardised cryptographic equipment. The DCE interface supports all the modem data rates required by MIL-STD-188-110D (Blocks 1, 2 and 3) up to 120 kbps. Please note that this standard includes several very unusual rates not normally found on serial interfaces.

In addition, the RC10 unit has three Ethernet interfaces for data transfer and management functions via UDP/IP and TCP/IP as summarised below.

• J13 DATA LAN port is used for the protocol data unit transfers via TCP/IP between the RC10 and the RM10 when synchronous serial transfers are not required.
• J14 CTRL LAN port is used for device management. The J14 CTRL LAN port supports up to three logical connections. The J14 CTRL LAN port is also used to interface with an external Network Time Protocol (NTP) server for accurate system time.
• J35 AUX LAN port is used to interface with the data applications used with the embedded STANAG 5066 stack or STANAG 4691 controller functions.

The RC10 also provides a serial interface for remote control and connections to an external GPS device for accurate system time. The RC10 units can also be configured and controlled via the front panel interface.