In traditional wireless conference systems, stability and reliability are key advantages, along with strong confidentiality and resistance to interference. However, these systems often impact the aesthetics of a room and complicate installation and maintenance. Especially when there is a need for frequent rearrangement of tables and chairs or mobile use across different rooms, wireless systems without physical connections have become increasingly appealing to users.
Wireless transmission technology was first introduced in simultaneous interpretation systems within conference setups. In recent years, wireless discussion systems have gradually evolved. This is because simultaneous interpretation systems primarily focus on multi-person listening, without needing to handle more complex features like "application," "priority," or two-way communication that are common in discussion systems.
First, the wireless simultaneous interpretation system.
Currently, there are three main modes of wireless simultaneous transmission: low-frequency, infrared, and ultra-high frequency (UHF).
(1) Low-frequency transmission system: Also known as an electromagnetic induction system, it uses a loop line within the listening area, driven by a high-power audio amplifier to create a strong electromagnetic field. Listeners use headphones connected to a core coil and amplifier. While this system is simple and cost-effective, it suffers from poor sound quality and stability. Low-frequency electromagnetic fields can penetrate walls, leading to weak confidentiality. Therefore, they are ideal for environments like museums, science centers, and large exhibition halls where multiple sub-sites share the same system. In such cases, the disadvantages of this system actually become advantages.
(2) Infrared transmission system: Infrared (IR) refers to electromagnetic radiation just beyond visible red light, with frequencies above 2 MHz. Since infrared rays do not pass through walls, they offer good confidentiality and are resistant to radio interference and eavesdropping. This system is known for its stable performance and superior sound quality, making it the mainstream choice for simultaneous interpretation. Recently, infrared technology has shifted from the earlier Band II (45 kHz to 1 MHz) to the higher Band IV (2 to 6 MHz) to avoid interference from energy-saving lamps and high-frequency light sources. Band IV also offers wider frequency response, better signal-to-noise ratio, and less channel interference, resulting in improved sound quality.
(3) UHF transmission system: This refers to broadband-based G-band digital simultaneous transmission systems developed in recent years. For example, the GONSIN 2.4 GHz wireless digital system uses Direct Sequence Spread Spectrum (DSSS) encryption, providing reliable anti-eavesdropping capabilities. It has a reception range of 80–100 meters and supports 2–16 voice channels (with 8 being standard). Compared to infrared systems, UHF systems allow non-directional reception, are unobstructed, and are less affected by energy-saving lamp radiation, making them suitable for less restrictive venue environments.
Second, the wireless conference discussion system.
There are several types of wireless conference discussion systems:
(1) Hybrid wired-wireless conference system: Early versions used wired transmission between delegates, chairpersons, and the main control unit, while wireless transmission was only used between the main control unit and the audio mixer (using V or U bands). This approach offered low cost and stable performance, but due to limitations in flexibility and confidentiality, it saw limited adoption.
(2) U-band wireless conference system: Each chairperson and delegate unit uses a separate gooseneck wireless microphone with different frequencies, and receiving units are stacked into a small cabinet. The system benefits from mature technology, a simple structure, and low cost. However, it lacks control functions, supports only free speech mode, and has limited simultaneous units and poor confidentiality. It is mainly suitable for small, budget-friendly meeting rooms.
(3) G-band wireless conference system: Its core technology is similar to the G-band simultaneous transmission system but includes more advanced features. Operating at 2.4 GHz, it can support up to 200 units simultaneously. It uses DSSS encryption, offering functionality comparable to wired systems, including "application for speaking," "sound control," "priority," voting, and eight-channel interpretation. Widely adopted in Chinese government agencies and enterprises, it performs well, though it comes at a higher cost.
(4) Infrared conference system: This system consists of a central control unit, transmitting/receiving units, and representative speaking units. Each speaker unit includes a transmitter, receiver, microphone, speaker, and rechargeable battery, communicating via infrared within a 7-meter range. The transmitting/receiving unit connects to the central control unit via coaxial cable. Beyond discussion, it supports simultaneous interpretation (two languages) and voting.
The infrared conference system is considered a promising new option, although it still lags behind wired systems in terms of confidentiality, stability, and the number of simultaneous units. The distance between the speaker and receiver is limited to 5–7 meters, which restricts its application in larger spaces.
Comcn Electronics Limited , https://www.comencnspeaker.com