100km TDD bidirectional video data wireless transmission

100km TDD bidirectional video data wireless transmission Appearance

Version history

Date	Version	Modification description
20231219	V1.0	Initial version
20240315	V2.0	Modify the weight dimensions, modify the total data in Table MCS & Wrażliwość
20240405	V3.0	Add multiple sets of coexistence switches. Modify the serial-to-network configuration mode. Modify the ID number length and modify the English words of background noise detection. Added the frequency matching function

Przegląd

Vcan1933-8-Watt PA is a self-developed TDD bidirectional graph integrated wireless transmission device. The product has the functions of real-time interference detection, adaptacyjny wybór częstotliwości, adaptive stream, automatyczna retransmisja, and automatic power control, which greatly improves the ability of anti-multipath and anti-interference, and has the characteristics of high reliability, dobra stabilność, and low delay.

This product is suitable for firefighting, kontrola, monitorowanie, and other scenarios,  and can transmit 100KM under good air-to-ground vision.

Product Characteristics

• Support long-distance transmission: 4M code flow can be transmitted up to 100km.
• Supports large bandwidth transmission: Up to 17Mbps@10MHz.
• Supports automatic repeater transmission: Supports automatic trunk addition.
• Supports multi-interface design: The device has two network ports and four serial ports, supporting RS232/TTL/RS422/SBUS.
• Supports automatic frequency selection: Automatic detection of interference signals, real time selection of the optimal frequency point.
• Supports automatic retransmission: Automatic retransmission of burst error data improves data reliability.
• Supports adaptive stream: The channel modulation mode is automatically adjusted according to the signal quality in real time.
• Supports automatic power control: Close range automatic adjustment of transmission power, reduce power consumption.
• Supports automatic antenna selection: According to the occlusion situation, the optimal antenna transmission is selected in real time.
• Supports the coexistence of multiple set: Support up to 6 sets of equipment at the same time fixed frequency use.
• Supports the frequency matching function: Software can be used to configure the frequency and hardware key frequency.

Specyfikacja

System parameter	Technical index
Equipment model	Vcan1933-8W
częstotliwość pracy	1350~1470MHz
Radio frequency	2T2R
Moc transmisji	39dBm (8-watt PA)
Transmission distance	100KM (Air-to-ground LOS)
szerokość kanału	10MHz
tryb modulacji	QPSK/16QAM
Receiving sensitivity	See Table (MCS & Wrażliwość)
Speed	17Mbps@16QAM3/4
Communication encryption	AES256
Transmission delay	≤10ms
Radio frequency interface	SMA*2
Equipment interface	XT30PW-M
Equipment interface	100Mbps Ethernet*2
	TTL/RS232*2
	RS422*1
	SBUS/TTL*1
Overall power consumption	≤48W@4Mbps(Air uint)
	≤12W@1Mbps(Ground uint)
Wymiar(L*W*H)	163*77*25mm
Waga	340sol
napięcie robocze	DC22~30V,Typical value: +24V@2A
Temperatura pracy	-40~+75℃

MCS & Wrażliwość (10MHz)
No.	MCS	Total uplink and downlink throughput (Mbps)	Wrażliwość (dBm)
1	QPSK1/3	4.0	-99
2	QPSK1/2	5.8	-98
3	QPSK2/3	7.1	-97
4	QPSK3/4	8.2	-96
5	16QAM1/3	8.0	-96
6	16QAM1/2	11.6	-95
7	16QAM2/3	14.3	-93
8	16QAM3/4	16.4	-91

Product dimension and weight

Dimension diagram

Dimension and weight

• Wymiar (L*W*H): 163mm*77mm*25mm(including SMA 10mm)
• Waga : 340sol

Product interface definition

Interface diagram

The interface of the Vcan1933-8W device includes the XT30PW-M power interface and J30J-25pin data interface. The interface has RS232/TTL*2, RS422*1, SBUS/TTL*1 and 100 Mbit/s Ethernet*2.

Interface definition

Power interface: XT30PW-M. Power supply range: DC22-30V Typical value:24V@2A

Linear order.	Pin name	Interface definition	Interface description	Signal direction
1,2,3,4	GND	Grunt	Grunt
5	422ZA	Serial port 3 RS-422	Receiving data RX+	ja
6	422B		Receiving data RX-	ja
7	422Z		Transmitting data TX-	O
8	422Y		Transmitting data TX+	O
9	TXD_A	Serial port 1 RS232/TTL	Transmitting data TX	O
10	RXD_A		Receiving data RX	ja
11	TXD_B	Serial port 2 RS232/TTL	Transmitting data TX	O
12	RXD_B		Receiving data RX	ja
13	GND		Serial port 2 ground	O
14	SBUS /TTL TX	Serial port 4 SBUS/TTL	SBUS/TTL sending	O
15	SBUS /TTL RX		SBUS/TTL receiving	ja
16	SBUS/TTL GND		SBUS/TTL ground	O
17	TX1P+	Network port 1	Transmitting data TX+	O
18	TX1M-		Transmitting data TX-	O
19	RX1P+		Receiving data RX+	ja
20	RX1M-		Receiving data RX-	ja
21	GND	Grunt	Serial port 1 ground	O
22	TX2P+	Network port 2	Transmitting data TX+	O
23	TX2M-		Transmitting data TX-	O
24	RX2P+		Receiving data RX+	ja
25	RX2M-		Receiving data RX-	ja

• Notatka 1: Signal direction I indicates radio input and direction O indicates radio output.
• Notatka 2: When using the serial port 1/2 of the device, please check whether it is TTL level or RS232 level.

jandicator Meaning

The RSSI light represents the strength of the received signal
Number of RSSI energy lights on	Received energy dBm
3 RSSI lights on	about -50dBm
2 RSSI lights on	about -80dBm
1 RSSI light on	about -95dBm

Module type	Tryb	Vcan1933-8W light status
		PWR	SYNC	LAN 1 LAN 2	RSSI 123
master	Un-sync	Powered on	Flashing	Data sending and receiving, flashing	Wyłączony
master	Sync	Powered on	Steady on	Data sending and receiving, flashing	Proportional to the strength of the received signal
slave	Un-sync	Powered on	Flashing	Data sending and receiving, flashing	Searching
slave	Sync	Powered on	Steady on	Data sending and receiving, flashing	Proportional to the strength of the received signal

When the master and slave devices are not synchronized, the PWR indicator of the master and slave devices is steady on, the SYNC indicator is blinking, and the RSSI indicator of the master device is off. The RSSI of the slave device will always be in the search state. After the master/slave synchronization, the SYNC indicator of the master/slave is steady on. The master-slave RSSI lamp displays the received signal energy intensity. When the network port is sending or receiving data, the master and slave devices correspond to LAN1, and the LAN2 indicator blinks.

More information about the product

TDD (Time Division Duplexing) is a communication technique used in wireless systems where the uplink (transmitting data from the ground control station to the drone) and downlink (transmitting video and data from the UAV to the ground receiver or GCS) share the same frequency channel but operate in different time slots. This allows bidirectional communication without requiring separate frequency bands for each direction.

TDD Protocol Optimization

• Ensure proper time slot allocation between uplink (sending data) and downlink (receiving data) for efficient bidirectional communication.
• Adaptive TDD allows dynamic allocation based on data traffic needs.
• Useful in applications where uplink and downlink traffic are asymmetric (np., video streaming).

Comparison Between TDD and FDD

Funkcja	TDD	FDD
Spectrum Usage	Single frequency band	Separate bands for uplink and downlink
Traffic Adaptability	Highly adaptable to asymmetric traffic	Fixed uplink/downlink ratio
Equipment Complexity	Lower cost and simpler hardware	Requires duplexers, increasing cost
Channel Reciprocity	tak, supports advanced techniques like beamforming	Nie
Interference	Requires strict synchronization	Less prone to interference

TDD is widely used in modern communication systems, including those requiring long-range bidirectional video transmission due to its efficiency and flexibility.

Power and Size Constraints:

• Lightweight hardware to minimize the impact on drone flight performance.
• Low-power consumption design to maximize drone battery life.
• Compact form factor to fit within the drone’s payload.

Antenna System:

• On Drone: Fiberglass omnidirectional or small directional patch antennas.
• Ground Station: High-gain parabolic, Yagi antennas or flat panel antennas with tracking systems for long-range communication.

Aplikacje

1. Surveillance and Security: Real-time video streaming from drones for law enforcement or border control.
2. Nadawczy: High-definition aerial footage for live events or media.
3. Agriculture: Monitoring crops and livestock over vast areas.
4. Disaster Response: Sending live video from disaster sites for better coordination.

Plik transmission range of an 8-watt power amplifier (ROCZNIE) depends on a variety of factors, including:

1. Pasmo częstotliwości: Higher frequencies experience more signal loss over distance (higher free-space path loss).
2. Antenna Gain: The type and gain of the antenna at both ends (nadajnik i odbiornik) significantly impact the range.
3. Environmental Conditions: Factors like terrain, buildings, weather (rain, fog), and line-of-sight (LoS) can affect range.
4. Modulation Scheme and Data Rate: More complex modulation schemes (np., QAM) and higher data rates may reduce effective range due to higher sensitivity to signal degradation.
5. Receiver Sensitivity: The ability of the receiver to detect a weak signal at a specific distance.