low-cost UAV Radio Data Link

low-cost UAV Radio Data Link

1. Introduction 

The digital data link modules are used for the communication between UAVs and the  ground station (GS) to send data and receive commands. The two-way radio link must have  high reliability and always be connected during the flight. Link module on UAV side must have  a low price due to limitation on UAV total cost in mass production. 

The main feature of this data link is the low rate of sending and receiving data to reduce the  occupied bandwidth and subsequently increase the sensitivity of modules.

Notes 1: The GS module must be capable of communicating with 12 UAVs simultaneously.  

2. Technical specifications

Parameters	Value
Maximum Operating Range	25km
Operating Height	10-5000m
Max UAVs Speed	100m/s
Frequency Band	UHF (upper 400MHz)
Frequency Channel Selection	Yes
Frequency hopping	Optional (is preferred)
UAV module Transmit Power	2W
GS module Transmit Power	10W
Data Rate	See the below figures (software selectable in range of 1kbps to 500kbps)
Packet transmission delay	≤ 5 millisecond
Error detection	CRC
Channel Coding (FEC)	Yes
Encryption	Yes
Senstivity	−122dBm@20kbps −199dBm@40kbps −111dBm@230kbps −108dBm@500kbps
MIMO Antenna	Optional
Operation mode	Point to Point (GS to one UAV) Point to MultiPoint (GS to maximum 12 UAVs on air, simultaneously)
Receive satuation power	10dBm
No damage receiver power	20dBm
Boot time	Less than 2sec
Operationg time	Maximum 30 minutes continuously
Working tempearure	−20°𝐶 ~ + 60°𝐶

Three working modes for this digital data link can be considered, which are described in the  following figures. According to the complexity and the cost of link module (specially on UAV  side), each topology can be selected. 

3. Networking Type

1- The working frequency of all uplinks and downlinks are different (the nodes work in  different channels). 

2- The frequency of uplink and downlink for each node is the same but is different with other nodes.

3- The working frequency of all nodes is same as other nodes and GS is managing the  nodes to avoid data loss and interference. 

Notes 2: In all the above three topologies, frequency hopping is a great advantage but is not a  critical feature.

4. Electrical and Interface

Parameters	Value
UAV Installed Module
Input Voltage	9~18V
Serial Port	1, RS422
Serial Baud Rate	9600~460800bps,
Antenna Connector	SMA
Interface Connector	J30J or DB type
Weight	Less than 150g
Size (LxWxH)	8 × 8 × 3 cm
GS Installed Module
Input Voltage	9~18V
Serail Port	1, RS422
Serial Buad Rate	9600~460800bps,
Ethernet	RJ-45, 100Mbps
Antenna Connector	N-Type
Interface Connector	J30J or DB type
Weight	Less than 500g
Size (LxWxH)	15 × 10 × 4 cm

Our low-cost UAV Radio Data Link does not has ethernet port, only serial port. The antenna connector is not N-Type, but SMA-Type. please check the below link.