WALKIE-TALKIE

1. Development of wireless communication systems

In today's rapidly developing society of information technology, wireless communication technology has been popularized in the lives of all people. Wireless communication technology is not limited to voice calls, it has been fully applied in business, daily life, finance, and work. Mobile phones, voice calls, digital television, network communication, data exchange, etc. have all emerged with the proliferation of wireless communication technology platforms. People only need a mobile or fixed terminal device, and can enjoy convenient services such as voice or video calls, data and exchange, images and faxes brought by wireless communication technology anytime, anywhere

The spread of wireless communication cannot be separated from the use of wireless devices. However, these wireless devices may also encounter some problems during use, resulting in computer data loss and inability to operate normally, bringing economic losses to enterprises and units. The main reasons for equipment failures are three aspects: firstly, enterprises and units do not regularly inspect and maintain the equipment during use, Secondly, there are deficiencies in the technical level and business capabilities of maintenance personnel. Thirdly, enterprises or units often choose equipment categories with low configuration, poor quality, and service life to reduce costs when purchasing equipment, undoubtedly increasing the probability of equipment failure

2. Development History of Underground Wireless Systems in Coal Mines

The earliest underground communication system in coal mines was the use of wired telephone systems. Although this type of phone serves as a communication device, it is very inconvenient. Fixed telephone, fixed usage, does not provide flexibility for scheduling. This situation creates requirements for wireless communication systems

The development of wireless communication in coal mines can be divided into: coal mine leakage communication, coal mine underground wireless communication system, and coal mine WIFI wireless communication system. The underground 3G wireless communication system in coal mines is divided into: mining TD-CDMA system, mining TD+WIFI system, and mining W-CDMA system. The underground 4G wireless communication system in coal mines is also divided into FDD-LTE and TD-LTE for mining purposes

1. Underground leakage communication in coal mines: The underground leakage mobile communication system utilizes the radial radiation characteristics of leakage cables and bidirectional relay amplification technology to achieve bidirectional long-distance transmission of radio waves in shielded spaces and underground tunnels. Solved the bifurcation transmission of radio waves in the tunnel, thus establishing a tree shaped wireless communication network for underground tunnels. The drawbacks of leaked communication are also evident to everyone: short transmission distance with limitations, difficulty in laying cables during construction (leaked cables are relatively thick, old, and bulky), and complex maintenance in the later stage. The ultimate drawback of leaked communication is poor call sound quality

2. Underground Xiaolingtong System in Coal Mines: Later, with the completion of Xiaolingtong's explosion-proof certification, some coal mines installed this system underground. However, with the delisting of PHS, many coal mines are no longer able to purchase new accessories, which has brought great trouble to the maintenance of the system. The basic situation is that many coal mines, due to the inability to guarantee the after-sales service of Xiaolingtong, are no longer suitable for this system and treat it as a decoration. Therefore, the application of wireless communication systems in coal mines has been placed on the agenda of coal mine communication system manufacturers

3. Coal mine 3G wireless communication system: 3G services can simultaneously transmit sound and data information, with a speed generally exceeding several hundred kbps. Underground communication in coal mines has also kept up with the pace of the communication era and developed. Typical applications include TD-SCDMA and CDMA2000 wireless systems, which are widely used in the mining industry. With the full coverage of 4G applications, 3G has gradually entered the delisting stage

With the development of wireless communication technology, 4G communication has emerged. Now, the general public has fallen in love with the wireless data experience brought by 4G communication. It can be said that we can no longer tolerate the days when mobile phones do not have 4G networks. So it will inevitably bring new applications and development of mining 4G

Since 2017, some coal mine product enterprises have gradually promoted underground 4G communication systems, with 4G uplink/downlink speeds of 50Mbps/100Mbps respectively, to gain the attention of coal enterprises

Considering the current communication development needs of coal mines, the high-speed network has basically completed the coverage of 10000 megabytes, gigabit branches, and 50M bandwidth, which cannot meet the current application needs of coal enterprises

Many people still insist that with the development of communication technology, the construction of 4G communication in coal mines has become an inevitable trend

However, in 2019, which is the first year of 5G, with the arrival of 5G and following the trend of wireless communication system development, 5G replacing 4G is unstoppable and an inevitable path for the development of wireless communication

So, as time goes by, it will inevitably lead to a situation where 4G systems will be unsupported and without product supply in two to three years

5. Coal mine WIFI communication system: Wireless technology is still constantly developing, and we have also seen rapid changes in WiFi. With the development of the Internet, the Internet of Things, new standards, cloud hosted WiFi, and other trends, we will also usher in more new milestones and developments in the WiFi field. According to the discussion and summary of relevant personnel and experts, future WiFi predictions:

By 2020, the number of IoT devices is expected to reach 10 billion. This rapid growth will continue to drive high-density demand for networks, including WiFi. We are about to usher in an era where the majority of global internet traffic will begin or end with WiFi

In recent years, it has been difficult for us to connect the growing number of IoT devices to WiFi, and we will continue to improve in the future. IoT devices will lead us into the world of all WiFi

We see a gradually clear competitive landscape between LTE and 5GHz band WiFi. Despite changes in data costs, the use of LTE is still limited, deployment costs are high, and typically billed per byte. On the other hand, WiFi deployment is cheaper, providing faster operational speed, and in almost all cases, it is provided free of charge to end users

Although development work is still ongoing around the 2.4GHz and 5GHz ISM frequency bands, in the coming years, most devices and networks will still use these two frequency bands, while increasing the use of the 5GHz frequency band. In this frequency band, the next major improvement is in 802.11ax, which will provide higher speed and spectral efficiency than 802.11ac

WiFi can now even be included in Maslow's basic human needs. In addition to clean water, food, and shelter, internet connectivity is now considered a basic need for many people. Just as everyone should be able to obtain the basic needs of life, our society should ensure that these needs are met

3. Underground wireless system demand space in coal mines

With the improvement of production efficiency and quality of life, the informatization construction of various industries has become complex and diverse. Owners need to timely understand and grasp the complex comprehensive information of equipment work, personnel work conditions, environmental conditions, information exchange, and other scenarios. Therefore, the requirements for wireless communication networks, especially in terms of effective signal coverage, network construction cycle, construction and maintenance costs, harsh weather, and complex environments, are very urgent

The rapid construction of a high capacity, controllable distance, and uniform coverage on-site wireless network is the main feature of the STRINGLINK wireless smart network solution. STRINGLINK relies on a high-performance wireless transmission system with multiple hops and controllable distance, which greatly reduces the construction workload of wired networks such as optical fibers through 2.4GHz/5.8GHz high-frequency microwave wireless networks. It can fully meet various complex indoor and outdoor scenarios, and ultimately achieve complex network data transmission and various data applications through 5-10 hop wireless networking, solving the problems of long implementation cycle, high cost, and difficult maintenance of traditional cabling solutions