Hierarchical Networking Waveform

The Hierarchical Networking Waveform (HADŞ) aims to establish a common network and communication for a large number of units (over 1000) using a single waveform within the same physical cycle. This provides a much more dynamic, robust, and scalable solution, free from the issues faced by existing waveform solutions.

Problems Faced in Military Waveforms

In existing military waveforms, the number of units that can be included in each network is limited. Therefore, thousands of units can only create a network by connecting dozens of networks, each formed by about 20-100 units, through specially defined “network transition units.” The connected networks often use different waveforms, and even if they use the same waveform, different frequency sets are adopted to prevent interference. This situation brings along many problems.

Having Different Waveforms or Frequency Sets Among Networks

  • A special conversion protocol is required for message transmission between different waveforms.
  • Coordination of user/control messages and services expected to be common across all networks is necessary for different waveforms.
  • As the number of connected networks increases, planning the frequency set and managing interference becomes more challenging.
  • Searching for networks within range without disconnecting from the current network is very difficult and inefficient.
  • Due to mobility, units disconnect from their networks and switch to more favorable networks, leading to service interruptions.
  • Resources that remain unused in networks with low traffic cannot be utilized in other networks.

Mandatory Use of Network Transition Units

  • Units that can communicate directly must do so through network transition units and transmitters because they are in different networks.
  • Even if multiple network transition units are used for network connectivity, the single point of failure situation cannot be completely resolved.
  • Bottlenecks occur on network transition units due to topology and traffic.
  • Special precautions for interference management are required on network transition units, increasing both device size and cost.

Connecting Different Networks with Gateway Units

Advantages Provided by Hierarchical Networking Waveform

All problems listed under Problems Faced in Military Waveforms have been solved with HADŞ.

With HADŞ, a hybrid solution has been created by combining the capabilities of different waveforms operating in “centralized” or “distributed” structures.

  • All units are combined into a single network that uses the same frequency sources.
  • Management of the network and resources is provided by group heads, which are determined dynamically and distributed by the waveform.
  • Group heads centrally manage their member units while working in a distributed manner among themselves.
  • Intra-group communication uses OFDMA, while inter-group communication uses TDMA in a hybrid manner.
  • Transitions between member and group head roles for units are managed independently of the user by waveform control.
  • Units can be defined as pre-assigned group heads or members based on their location, hardware, battery, and other features.

Gathering All Units in a Single Network

With the design of HADŞ:

  • All user services provided by existing military waveforms are supported (Push-to-talk, point-to-point voice, video/file/message transfer, etc.).
  • It is designed to be scalable and suitable for hierarchical structures.
  • It has effective repair mechanisms under mobility.
  • It can adapt to connection quality and data traffic.
  • It does not rely on any GNSS.
  • It can operate in a distributed manner.
  • It possesses efficient channel access mechanisms within and between groups.

To enable all these capabilities, numerous access control and network layer protocols have been developed. Each layer is designed and tested not only on its own but also as a whole with other layers. The validation of these protocols, which can operate in a distributed or centralized manner, has been conducted through applications such as TSim and TMC. Validations have been performed in homogeneous and clustered networks with 50, 100, 200, 500, and 1000 units, involving various mobility, opening, and traffic model scenarios.

The first version of the HADŞ design is scheduled for delivery to ASELSAN in January 2025. The physical layer of HADŞ has been developed by ASELSAN, while the upper layers have been developed and validated by ARKETEL under ASELSAN’s supervision and support.