Waveforms for LOS/BLOS communications

The national implementation of cryptographic algorithms safeguards all of a radio’s characteristics that are relevant for national security. After approval of the software by the security authorities, the waveform can be downloaded onto the software defined radio (SDR) in compliance with the security regulations. This flexibility opens up additional opportunities for enabling interoperability of the communications technology between partners: For example, interoperability between the armed forces (joint missions), between allies (combined missions) and even with public safety organizations.

Waveform development in the context of software defined radio has to address topics beyond waveform development for legacy systems (e.g. for HF modems). The key requirements of modern software defined radio based waveform development are met by using a defined approach to waveform development for all waveform development steps. The radio and radio platform software is based on the SCA 2.2.2 standard.

Figure: Translate technical capabilities into user-oriented operational benefits
Figure: Translate technical capabilities into operational benefits


The different waveforms of software defined radios need to cover all required applications/use cases such as situational awareness, live video transmission, command and control, and simple voice communications. There are different design aspects to be considered when developing a waveform for tactical communications:

  • Robustness and mobility
  • Jam resistance
  • Low probability of detection and interception
  • High data rate
  • High range and coverage
  • Networking capability (MANET) and quality of service
  • Adaptability

The individual properties partly influence each other physically. Different waveforms are needed to adapt the technical settings to the mission scenario.
Example: A waveform suitable for air-ground communications must cope with the high speed of the airborne platform, and therefore must include Doppler shift compensation. This is not necessary for ground-ground communications.

Translate technical capabilities into operational benefits

For example, the use of SCA (software communications architecture) based waveforms for SDR (software defined radios) enables:

  • Independence of software from specific hardware solutions
  • Scalability in terms of radio channels and radio platforms (handheld to airborne)
  • Portability of application software between different SCA implementations
  • Reduction in development time for a new waveform through the ability to reuse modules

Interoperability is not only important for protecting national interests, it is also essential for allied missions. Rohde & Schwarz provides access to suitable tools for porting legacy and modern innovative waveforms. This gives the end user backward compatibility to existing waveforms and radio systems as well as investment security for future scenarios ("joint & combined").

Rohde & Schwarz even offers you the possibility to design and operate your communications solutions completely independently from manufacturer or other governmental influence.

Figure: Line of sight (LOS) waveforms
Figure: Line of sight (LOS) waveforms

Line of sight (LOS) waveforms

Supported by software defined radios in the R&S®M3xR VHF/UHF radio families.

All line of sight (LOS) waveforms have in common that they do not use a communications infrastructure like base stations. These waveforms are designed to operate in a harsh environment where it is imperative that a loss of infrastructure does not lead to a loss of communications. All waveforms are designed to achieve a very high point-to-point radiocommunications range without any infrastructure.

LOS waveforms for tactical applications are operated mainly in the frequency range from 30 MHz to 600 MHz, focused on some core bands. Military waveforms are designed to offer the highest standard of security features through COMSEC (e.g. encryption) and TRANSEC (e.g. frequency hopping) capabilities. Jamming resilience is also offered in the tactical military domain through highly capable RF frontends that can handle large collocated signals without degrading reception capabilities.

Supported by SOVERON® software defined radios.

SOVERON®WAVE provides the best options for transmitting secure high data rates in a jammed environment in various ground, air and combined ground-air-ground scenarios. Simultaneous voice and data capability significantly reduces the need for additional radios. The waveforms provide an increased situation awareness through adaptive high bandwidth IP networking. An embedded mobile ad hoc networking concept enables continuously stable communications within agile networks.

LOS overview

BLOS technologies overview

R&S®SECOM is a combination of COMSEC and TRANSEC optimized for LOS landbased applications. User data (voice or data) is transmitted completely digitally and in encrypted form.


In one R&S®SECOM-V net, several subnets and sublinks can be established simultaneously forpoint to-point and point-to-multipoint modes.

  • Frequency range: VHF/UHF (30 to 512 MHz)
  • TRANSEC: up to several hundred hops/sec
  • COMSEC: Embedded customized crypto algorithm, long key length


R&S®SECOM-P was especially optimized for use on small, lightweight terminal equipment like handheld radios. It provides automatic position reporting.

  • Frequency range: VHF (30 to 144 MHz)
  • TRANSEC: up to hundred hops/sec
  • COMSEC: Embedded AES, long key length
BLOS technologies overview

R&S®SECOS is a combination of COMSEC and TRANSEC optimized for LOS air-ground-air applications.Besides digital voice mode, data transmission with data rates of up to 16000 bit/s is supported. Using the time division multiple access (TDMA) method, data can be automatically exchanged between specified users. Each user can send its own data to the other users during its assigned timeslot. The number of available TDMA timeslots can be allocated to the operational requirements.

  • Frequency range: VHF and UHF (30 to 88 and 225 to 400 MHz)
  • TRANSEC: up to several hundred hops/sec
  • COMSEC: Embedded customized crypto algorithm
BLOS technologies overview


HAVE QUICK is a NATO TRANSEC algorithm optimized for LOS air-ground-air applications.

  • Frequency range: UHF (225 to 400 MHz)
  • TRANSEC: slow
  • COMSEC: Crypto units complying with NATO standards such as ELCRODAT 4/2 may be used as an external option.

SATURN - second generation anti-jam tactical UHF radio for NATO

SATURN is a NATO TRANSEC algorithm optimized for LOS air-ground-air applications.Backwards compatible with HAVE QUICK II. Provides digital voice and data up to 16000 bit/s.

  • Frequency range: UHF (225 to 400 MHz)
  • TRANSEC: fast
  • COMSEC: Crypto units complying with NATO standards such as ELCRODAT 4/2 may be used as an external option.
BLOS technologies overview


High range, high jamming immunity, low spectrum requirements and best possible data rate in tactical VHF band for uncompromising communications reliability. The network-capable narrowband waveform.


The all-purpose wideband waveform: Enabling mobile networked operations in jammed environments. Delivering high data rates and ranges, the ideal conjunction of security and performance.


Mobile networked, high data rates for the best radio system performance in terms of network capability and superior data rates

Multihop MANET topology

The SOVERON®WAVE multihop capability is based on the MANET functionality and supports the automatic exchange and distribution of voice and data transmissions within the entire network. Multiple radios will forward the messages directly.

Figure: HF house waveforms.
Figure: HF house waveforms.

BLOS (beyond line of sight) waveforms

Supported by software defined radios in the R&S®M3xR HF radio families.

The main purpose of beyond line of sight (BLOS) is to be able to have a long reach without the need for infrastructure. The main advantage of HF radiocommunications is the fact that the electromagnetic signals between 1.5 MHz and 30 MHz allow the use of reflection effects on the ionosphere to achieve extremely high ranges of thousands of kilometers without any infrastructure between the transmitter and receiver.

Modern automatic link establishment standards provide an automated capability to connect communications partners at any time and under any ionospheric conditions. These mechanisms use information about solar activity, geographical positions of the communications partners and the exact date. The available frequency spectrum is scanned and coordinated with potential communications partners. The results of connectivity over frequency range are stored and continuously updated within and by the radios.

With the development of new technologies such as WBHF, HF is no longer limited to voice and very small data rates. It can now also accommodate IP data, video and imaging and become an alternative to satellite communications.

BLOS overview

BLOS technologies overview

ALE 2G/3G - ALE software for automatic link establishment systems

ALE 2G provides support for the FED-STD-1045/1046/1049 and MIL-STD-188-141B App. A+B standards. ALE3G in line with STANAG 4538 offers significant benefits compared to ALE 2G, including considerably faster and more robust link setup, improved automatic channel selection algorithms and embedded data link protocols. In addition, the automatic link maintenance (ALM) functionality is supported.The R&S ALE 3G built-in xDL data link protocols are low-latency data link protocol (LDL) and high-throughput data link protocol (HDL).

  • LDL for small datagrams in all channel conditions: approx.300 bit/s
  • HDL for large datagrams in medium to good channel conditions: approx. 3400 bit/s
BLOS technologies overview

STANAG 4538 allows the radio to be directly used as a static IP router. The network layer, link layer and physical layer are embedded into the radio. This ensures high reliability and low maintenance costs since no additional hardware such as external modems is necessary.

R&S®STANAG 5066 is a communications solution for the robust and highly secure exchange of data using HF radio networks in line with STANAG 5066.

BLOS technologies overview

Enables self-identifying (auto-baud) data communications up to 12800 bit/s. It automatically adapts the receiving data rate and is used preferably with the STANAG 5066 data protocol. STANAG 4539 is based on more than one standardized modem waveform:

  • STANAG 4415 (very robust traffic waveform at 75 bit/s)
  • MIL-STD-188-110B (low and medium-rate serial tone waveforms from 150 bit/s to 2400 bit/s)
  • MIL-STD-188-110B App. C (high data rate waveforms from 3200 bit/s to 12800 bit/s)
  • MIL-STD-188-110B App. F (waveform uses independent sidebands for high-speed data transmission with up to 19200 bit/s).
BLOS technologies overview

R&S®SECOM is a combination of COMSEC and TRANSEC optimized for BLOS applications. User data (voice or data) is transmitted completely digitally and in encrypted form.To ensure reliable links even in severely degraded channels, free hop set search (FHS) is available. FHS is an algorithm for the automatic adaptation of hop sets based on channel evaluation. Data rates from 75 bit/s to 2400 bit/s are possible.

  • Frequency range: HF (1.5 to 30 MHz)
  • TRANSEC: slow
  • COMSEC: Embedded customized crypto algorithm, long key length



With sophisticated equalizers and unrivaled radio parameters that overcome even challenging sky wave propagation conditions, HF-WB is a competitive alternative to SATCOM links over large distances.

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