การประยุกต์ใช้ในอุตสาหกรรมของระบบโทรศัพท์ฉุกเฉิน GSM

We specialize in manufacturing and selling stainless steel call system auto dial telephone waterproof telephone for prison use with CE certification. This is a gsm phone with a metal case. You can install your phone indoors or outdoors. It is a freely movable landline that can be placed outdoors and is tamper-proof. A 3g or 4g sim card must be used for communication.
What is GSM?
GSM full name: Global System for Mobile Communications, Chinese is Global System for Mobile Communications, commonly known as “Global Access”, is a mobile communication technology standard originated in Europe, is the second generation of mobile communication technology, its development purpose is to make the world a mobile phone Web standards can be used together to allow users to travel the world with a single phone.

What is the difference between phone and gsm?
Ordinary analog phones and VoIP phones need to install network cables for communication. The gsm phone only needs a 3G or 4G sim card to communicate. GSM phones, without installation, are mobile phones.
How does GSM work?
1. GSM is a cellular network, which means that the phone connects to the closest cellular area it can search. GSM networks operate on many different radio frequencies.
2. There are four different cell sizes in the GSM network: macro cells, micro cells, pico cells and umbrella cells. Coverage varies by environment. A jumbo cell can be thought of as a type of base station antenna mounted on a mast or on the roof of a building. Micro cells are cells with antenna heights lower than the average building height and are generally used in urban areas. A picocell is a small cell with a coverage area of ​​only tens of meters and is mainly used indoors. Umbrella cells are blind spots that cover smaller cellular networks, filling in signal gaps between cells.
3. The radius of the honeycomb can vary from more than 100 meters to tens of kilometers, depending on the antenna height, gain and propagation conditions. The longest range in practice GSM specification supports up to 35 km. There is also the concept of extended cells, where the cell radius can be doubled or more.

GSM also supports indoor coverage, and the power of the outdoor antenna can be distributed to the indoor antenna distribution system through the power divider. This is a typical configuration for indoor high-density calling needs, commonly found in shopping malls and airports. However, this is not required, as indoor coverage can also be achieved with wireless signals passing through the building, but this improves signal quality and reduces interference and echo.

Key Features: Compatible with most PABX, PBX, PAX and VoIP systems. 1. The main body is an all-steel body, which is firm and temperature-resistant. Stainless steel body. (Optional) 2. Speakerphone, with or without keyboard. The front panel includes the microphone and speakers. 3. The well-treated metal keyboard is rust and corrosion resistant. 4. Automatic recovery of lightning protection, in line with ITU-T K21 standard. 5. The waterproof rating of the housing and electronic modules is IP65. 6. The metal shell is equipped with a ground connection device, which is absolutely insulated from the internal circuit and electricity, and plays the role of electromagnetic shielding.

 
7. Support hotline calls, which can automatically hang up when the other party is closed. 8. Ultra-thin and smart design. Inline and hanging styles can be selected. 9. Shell color (UV protection) and logo can be customized according to customer requirements. 10. The phone has passed ISO9001:2000 certification 11. Panel LED status display.

Applications: As indoor and outdoor public telephones, elevator telephones, taxi or bus stops or stations, highway telephone booths. Railroads, subways, ATM machines, tunnels, ports, docks, mines, power generation facilities… The ideal phone for use in wet or corrosive environments.