Answer :

Media Transfer Over Long Ranges via Low Bandwidth and Low Power Usage in Drones

1. Networking Architectures for Long Range

In recent years, due to rapid advancements in drone technology, usage of drones has also increased rapidly both for professional and recreational tools as well as for air sports competitions. However, it is the culmination of the various systems associated with the drone, both air and ground support equipment which makes use of drones in various purpose more viable and convenient. Reconnaitre Pty Ltd. is a company based in Melbourne which deals in drone research and development. The current flagship product of the company is a drone project that could help the farmers to locate and report livestock counting in rural communities as well. Thus, it would be beneficial if the media transfer from the drones could be possible over a longer range of distance.

As per Peshkova, Hitz and Kaufmann [2], drones, also known as Unmanned Aerial Vehicle (UAV), was initially using short-range networking technologies like Wi-Fi, Bluetooth or ZigBee for media communication purposes with the help of transmission variants like IEEE 802.11, 802.15.1 and 802.15.4. However, with the implementation of drone technology in a wide range of field, it is necessary to increase the range and still carry out the optimal level of media transfer over such long distances. Moreover, as stated by Jospin, Stoven-Dubois and Cucci [8], due to the unavailability of sufficient bandwidth and power source, it is necessary to develop power and bandwidth effective methods for long-range media transfer. It is through decentralized networking architectures like multi-layer, multi-group or simple ad-hoc network, optimal transfer of media and communication can be performed. It is the FANET architecture that enables a UAV to UAV communication transfer of media information, thus enabling a long-range system. In this architecture, as mentioned by Kaleem and Rehmani [5], the drones perform dual actions where the UAVs are used as remote access units to compensate for the infrastructural coverage as well as utilize heterogeneous resources to form a dynamic network. However, as suggested by Joh, Yang and Ryoo [4], for this architecture to work, two networking modes viz. U2I and U2U have to be operational at all times. One of the drones acts as the backbone UAV to provide the common gateway in the FANET architecture. It is by collecting media information from the member drones in the network and transmitting the same to the ground station, a longer-range coverage can be achieved. However, using a centralized architecture with a ground station as a central node is not convenient which ensures the use of decentralized network architecture for long-range transmission. 

According to Khan, Qureshi and Khanzada [6], as for wireless communication technologies that need to be used in the FANET networking architecture is compatible with the decentralized structure for ensuring long-range coverage. Nevertheless, these technologies still require the transfer of media information over U2U while a fixed infrastructure of U2I stays intrinsic to it. Such long-range communication technologies include WiMAX, Long-Term Evolution (LTE), 5G or SATCOM [2]. With a supportable maximum data rate of 75 Mbps, the WiMAX is capable of transmitting high-quality video and voice streaming services and is currently the most popular choice of technology in UAV-based rescue operations where the surrounding environment is hostile. On the other hand, the LTE offers enhanced control along with high data rate and secure wireless connectivity which enables the UAVs to act beyond the visual LOS. Moreover, this communication technology is suitable for low-high bandwidths ranging from 5 MHz to 20 MHz of bandwidths. Furthermore, as pointed out by Hayat, Yanmaz and Muzaffar [3], the compatibility of both Frequency Division Duplexing (FDD) and Time Division Duplexing (TDD) provides a wider range spectrum ranging from 5 km for optimal performance to 100 km for acceptable performance. The use of 5G provides excellent quality support for media transfer due to its high-data-rate, reduced latency, ubiquitous capacity and enhanced energy saving and system capacity. Considered as the latest generation in cellular mobile communication, it requires speed bandwidth of 100 GB/s which can support an enhanced capacity by a factor of 1000. It is due to this high bandwidth requirement; it is rarely used in rural areas despite having the energy-efficient capability.

3. Low Bandwidth Usage

This is probably the most ideal choice of communication technology for carrying out media transfer in long-range and also at low bandwidth usage. According to Zhu, Otey and Fan [7], this technology uses electromagnetic signals which can cover large distances and hence used for sending signals from ground stations to space stations. Moreover, it also supports a varied range of frequency bands due to the use of multiple satellites for transmitting media information. For instance, the C-Band uses an uplink of 6 GHz while a 4 GHz is used for the downlink. The military or governmental bodies use a slightly higher bandwidth from the X-Bands that offers 8 GHz for the uplink and 7 GHz for the downlink. According to Joh, Yang and Ryoo [4], when implemented for UAV media transfer functions, the larger overlay range of this technology provides an image transmission over a larger area while maintaining high image quality. Despite having a high-cost data transmission rate, the bandwidth for this system is significantly low. However, this low bandwidth capacity often results in live image and video transmission problems and optimal quality is not received by the user. However, when considering both long-range media transfer and usage of low bandwidth, SATCOM is ideal and can be used with the FANET networking architecture for meeting the requirements.

4. Low Power Usage

On-board energy limitation is probably one of the major challenges that specialist developer engineers face when upgrading drone components and technologies. The only way of lower power usage for a UAV is the achieving of objectives with minimal use of the onboard power. One of the major ways to achieve low power usage is the cooperation between the UAVs (U2U) which enables the scope for one UAV at a time to abandon its mission and maximize its power reserve capacities. In addition to this, as suggested by He, Chan and Guizani [9] another mode of achieving a low power usage is the identification of an optimal trajectory for the drones through an analytical framework that is capable of minimizing the energy consumption rate. In fact, implementing architectures like Lora WAN ensures that the drones are deployed in a smart way derived from a firefly optimization algorithm and ensures maximum energy conservation for the UAV. Specialist development engineers are consistently working on long-range wireless video system and media transfer functions through low bandwidth and power usage to provide a smooth First-Person View (FPV) experience for the pilot remotely controlling the drone.