100km TDD bidirectional video data wireless transmission

100km TDD bidirectional video data wireless transmission Appearance

Cronologia delle versioni

Data	Versione	Descrizione della modifica
20231219	V1.0	Versione iniziale
20240315	V2.0	Modify the weight dimensions, modify the total data  in Table MCS & Sensibilità
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

Panoramica

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, selezione adattativa della frequenza, flusso adattivo, automatic retransmission, and automatic power control, che migliora notevolmente la capacità di anti-multipath e anti-interferenza, e ha le caratteristiche di alta affidabilità, buona stabilità, e basso ritardo.

Questo prodotto è adatto per la lotta antincendio, ispezione, monitoraggio, e altri scenari,  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.
• Supporta la selezione automatica dell'antenna: A seconda della situazione di occlusione, the optimal antenna transmission is selected in real time.
• Supports the coexistence of multiple set: Supporta fino a 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.

Specifica

Parametro di sistema	Indice tecnico
Equipment model	Vcan1933-8W
frequenza di lavoro	1350~1470MHz
Radiofrequenza	2T2R
Potenza di trasmissione	39dBm (8-watt PA)
Distanza di trasmissione	100KM (Air-to-ground LOS)
Channel bandwidth	10MHz
Modalità di modulazione	QPSK/16QAM
Sensibilità di ricezione	See Table (MCS & Sensibilità)
Velocità	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)
Dimensione(L*L*A)	163*77*25mm
Peso	340g
tensione di funzionamento	DC22~30V,Valore tipico: +24V@2A
Temperatura di lavoro	-40~+75℃

MCS & Sensibilità (10MHz)
No.	MCS	Total uplink and downlink  throughput (Mbps)	Sensibilità (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

• Dimensione (L*L*A): 163mm*77mm*25mm(including SMA 10mm)
• Peso : 340g

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.

Definizione dell'interfaccia

Power interface: XT30PW-M. Gamma di alimentazione: DC22-30V Typical value:24V@2A 

Linear  order.	Nome del perno	Definizione dell'interfaccia	Descrizione dell'interfaccia	Signal  direction
1,2,3,4	TERRA	Terra	Terra
5	422UN	Serial port 3 RS-422	Receiving data RX+	IO
6	422B		Receiving data RX-	IO
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	IO
11	TXD_B	Serial port 2 RS232/TTL	Transmitting data TX	O
12	RXD_B		Receiving data RX	IO
13	TERRA		Porta seriale 2 terra	O
14	SBUS /TTL TX	Serial port 4 SBUS/TTL	SBUS/TTL sending	O
15	SBUS /TTL RX		SBUS/TTL receiving	IO
16	SBUS/TTL GND		SBUS/TTL ground	O
17	TX1P+	Porta di rete 1	Transmitting data TX+	O
18	TX1M-		Transmitting data TX-	O
19	RX1P+		Receiving data RX+	IO
20	RX1M-		Receiving data RX-	IO
21	TERRA	Terra	Porta seriale 1 terra	O
22	TX2P+	Porta di rete 2	Transmitting data TX+	O
23	TX2M-		Transmitting data TX-	O
24	RX2P+		Receiving data RX+	IO
25	RX2M-		Receiving data RX-	IO

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

IOndicator 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

Tipo di modulo	Modalità	Vcan1933-8W light status
		PWR	SYNC	LAN 1 LAN 2	RSSI 123
maestro	Un-sync	Acceso	Flashing	Data sending and  receiving, flashing	Spento
maestro	Sync	Acceso	Steady on	Data sending and  receiving, flashing	Proportional to the  strength of the received  signal
schiavo	Un-sync	Acceso	Flashing	Data sending and  receiving, flashing	Ricerca
schiavo	Sync	Acceso	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. Quando la porta di rete invia o riceve dati, the master and  slave devices correspond to LAN1, and the LAN2 indicator blinks.

More information about the product

TDD (Duplex a divisione temporale) is a communication technique used in wireless systems where the uplink (transmitting data from the ground control station to the drone) e collegamento in discesa (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) e collegamento in discesa (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 (per esempio., video streaming).

Comparison Between TDD and FDD

Caratteristica	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	sì, supports advanced techniques like beamforming	NO
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.
• Stazione di terra: High-gain parabolic, Yagi antennas or flat panel antennas with tracking systems for long-range communication.

Applicazioni

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

Il raggio di trasmissione of an 8-watt power amplifier (PA) depends on a variety of factors, compreso:

1. Banda di frequenza: 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 (trasmettitore e ricevitore) significantly impact the range.
3. Condizioni ambientali: Factors like terrain, edifici, weather (rain, nebbia), e linea di vista (LoS) can affect range.
4. Modulation Scheme and Data Rate: More complex modulation schemes (per esempio., QAM) and higher data rates may reduce effective range due to higher sensitivity to signal degradation.
5. Sensibilità del ricevitore: The ability of the receiver to detect a weak signal at a specific distance.