Current Problems and Improvement Measures of Prison Mobile Phone Blocker

Dojammer 2022-01-04

one. Overview In order to meet the needs of the new situation, improve prison science and technology prevention capabilities, strengthen prison science and technology management, promote digital prison construction, promote the harmonious and stable development of prisons, and continuously improve the modernization level of prison work, it is necessary to scientifically and effectively control cell phone signals in prisons And prevent, put an end to the hidden dangers caused by illegal use of mobile phones.

two. Current status According to the relevant regulations of the Ministry of Justice and the spirit of the document, prisons across the country have had an urgent need to establish a mobile phone shielding system in recent years. Many prisons have prepared projects or have started construction projects. Looking at the current situation: some units have adopted high starting points and strict requirements. Through long-term market research, they have learned relevant successful experiences and failed lessons, and organized relevant experts to explain the technical questions of various brand enterprises and demonstrate the actual shielding effects of products. Currently, Shanghai prisons More than 92% of the prison shielding projects of the Administration have finally selected the best brand companies to undertake, and initial results have been achieved. However, due to many reasons, the expert team found that a large number of prison shielding systems across the country did not work well. Although some of these systems have been completed, they cannot operate normally. This has become a thorny issue for prisons and engineering companies.

three. Several main manifestations of poor effectiveness 1) The shielding area is not effective, there are a large number of blind spots, and blind spots. Some areas near the window of the cell, especially on the side of the base station, can be connected to mobile phones, or even certain areas. Some antennas (equipment) can still be used to talk, leaving opportunities for criminals and failing to fully prevent illegal use of mobile phones. 2) Serious interference in areas that should not be shielded: Office buildings, armed police and other areas outside the second door of the prison are severely interfered, affecting the normal life and work of the staff; more serious interference will be further expanded, and even the base station will be paralyzed by interference. Large areas of communities, factories, and units are subject to strong interference, and people are full of grievances; complaints from residents and operating departments such as China Mobile, China Unicom, and telecommunications, as well as investigations by local radio management departments, have brought a certain negative impact on the normal work of the prison , Disturbed the harmony between the police and the people. 3) Unstable system operation: good times and bad times, low reliability, frequent failures. Especially in the summer and autumn seasons, a large number of equipment failures and damages, although a large number of equipment replacements still cannot achieve the expected shielding effect; in exchange for continuous maintenance, life and money are exhausted.

Four. Several main reasons 1. Subjective understanding 1) Lack of a correct and comprehensive understanding of the essential difference between the prison shielding system and the common civilian mobile phone shielding devices on the market. The prison shielding system is a perfect organic combination of communication technology, radio wave transmission and reception technology, electronic countermeasure technology, equipment performance indicators and other comprehensive technologies and product indicators. It is not a simple distributed use of a large number of general civilian mobile phone shields. 2) Lack of comprehensive and scientific analysis of systematic cost-effectiveness and input-output ratio. People usually propose to invest the smallest amount of money to produce the greatest effect, but ignore the basic and reasonable investment in product technology. Even the purchase and use of low-end equipment products that are fundamentally incompatible with the technical requirements of prison projects have inherent deficiencies, leaving endless hidden dangers in the future. 3) Under the immediate economic interests, some corporate marketing personnel exaggerate the strength and product quality of the company, make promises that they do not understand and cannot achieve, and hold that if problems occur in the future, they will rely on their good social skills and customer relationships to make up for it. Hope that the product itself is problematic (even some equipment suppliers know that the product itself has serious defects). 2. The reason for the equipment itself 1) At present, many domestic manufacturers of shielding equipment have not invested a lot of manpower and financial resources in product development and application, and key technologies have not been improved accordingly. Instead, they adopt OEM, imitation, low cost, and low performance. , Low-price strategy, mass production and sales, relying on extensive and exaggerated marketing and promotion, and achieved a certain profit in the general civilian market where the requirements are not high. At the same time, it wants to occupy a place in the prison and other high-standard, high-demand, and high-reliable market areas. But in the end, it will inevitably bring immeasurable losses to the prison cell phone shielding system. 2) Reasons for design, installation and commissioning: Many companies undertaking shielding projects lack basic technical support for large-scale projects such as mobile phone shielding in prisons, lack considerable professional knowledge and rich application experience, lack the necessary testing equipment, and implement blindly and hurriedly. Individual designers, without knowing why, refer to the effective shielding range in the product manual for design distribution, and installers just complete the equipment fixation and power-on work. When the shielding effect is found to be poor, the method of increasing the number of equipment is simply adopted to achieve the shielding effect, and the project cannot be ended due to the loss of the other.

cell Signal Jammers

five. Countermeasures 1) Raise awareness of the essential difference between mobile phone shielding in prisons and ordinary civilian shielding devices. It is necessary to fully understand what is basic shielding, what is strict shielding, why civilian products cannot be used in professional fields, what kind of products are professional products, and the difficulty of prison shielding, etc. 2) Carry out meticulous market research, such as searching on the Internet, understanding related success and failure cases in the same industry, and fully communicating with relevant enterprise technical personnel, choosing strong technical force, advanced product technology, stable quality, good corporate reputation, and brand Companies and product brands that are well-known and can provide a large number of successful cases have carried out relevant cooperation. Of course, under the strict guidance of the prison authorities, commissioning a local reliable system integrator to conduct in-depth research and implementation can also achieve relatively good results.

six. Selection and identification of basic products (1) Product features that are absolutely impossible to choose: 1. Small size and light weight (generally less than six kilograms); 2. The shield is not directly connected to 220v, and an external power adapter is required; 3. There are adjustment devices on the shielding device that can freely change its shielding power and distance, such as power switch, power distance adjustment, etc.; 4. The output interface diameter of the shielding device is less than 15mm, and only a few small plastic sheath antennas can be connected, which is difficult to connect to a dedicated antenna. Antenna; (2) Product features that may be applicable 1. Large size, sturdy structure, large heat dissipation area, generally heavier than six kilograms; 2. The device does not have an external power adapter, but uses a 220V power supply directly inside the chassis. Voltage, undervoltage and overload short-circuit protection; 3. Non-professional manpower uses professional tools and instruments, which cannot adjust and change the output technical indicators of the equipment; 4. The shielded signal output interface should use a standard N-head, and the antenna and the equipment are connected and used separately through a 50Ω cable; 5 , The inside of the equipment is composed of CDMA, GSM, DCS, PHS, 3G (CDMA2000/TD-SCDMA/WCDMA) modules with various performance indicators and industrial-grade power packs as the core

seven. Choosing enterprises and products should do the work in the early stage. Relevant enterprise technicians are required to enter the prison site or simulated site and explain the technical plan, and demonstrate the actual shielding effect and anti-destructive performance of the equipment. Through the above work, understand the technical strength and equipment performance of related enterprises, prepare for the selected brand, and ensure that the project achieves good results.

Eight. Recommendations related to the prison mobile phone shielding system a) Requirements for the use of the shielding system 1. It acts on all current domestic public communication standard mobile phones CDMA, GSM, DCS, PHS, 3G (CDMA2000/TD-SCDMA/WCDMA), and shall not affect other electronic equipment in the prison The system is operating normally; 2. The effective shielding rate should reach 99.9% or more within the prison range (including but not limited to the prison room, walkway, corridor, window, etc.); 3. The effective shielding rate should reach 99% or more in the production area; 4. For confined narrow spaces (including but not limited to conversation rooms, storage rooms, toilets, etc.) and more hidden places with greater possibility of violations, the effective shielding rate should reach 99.9% or more; 5. Unshielded areas (including but It is not limited to the administrative building, the armed police building and surrounding units or residential living places, etc.), it must ensure smooth communication; 6. After the shielding effect is achieved, it must pass the shielding on-site electromagnetic radiation safety test; 7. Fully retain the equipment output redundancy and improve the use Longevity and adapt to future development requirements; 8. The system must use centralized power supply. b) Follow relevant standards and specifications 1. GB 8702-88 People’s Republic of China Radiation Protection Regulations 2. GB 9175-88 People’s Republic of China Environmental Radio Wave Sanitation Standards 3. GA/T 75-2000 Safety Precaution Engineering Procedures and Requirements 4. JCJ/T 16-92 Civil Building Electrical Design Code 5. Prison Cell Phone Shielding System Standard "Police Technology" 6. GB/T 50311-2007 Building and Building Group Integrated Wiring System Engineering Design Code 7. GB/T 50312-2007 Building and Building Group General wiring system engineering acceptance code 8. YD/T 5120-2005 wireless communication system indoor coverage engineering design code 9. YD 5039-97 communication engineering construction environmental protection technical regulations 10. YD 5098-2005 communication bureau (station) lightning protection and grounding Engineering grounding specifications c) Mainly use shielding technology 1. Mobile 3G TD-SCDMA must use time slot synchronization to shield the downlink pilot, and it is strictly forbidden to use methods that interfere with other line time slots to avoid strong interference or even paralysis of the base station . 2. For CDMA/CDMA2000, GSM, DCS, PHS and WCDMA and other standard frequency bands, the signal strength of the mobile phone is ≤ -55dBm, and the frequency band wideband frequency sweep method can be used. 3. For CDMA/CDMA2000, GSM, DCS, PHS, WCDMA and other standard frequency bands when the signal strength of the mobile phone is ≥-50dBm, narrowband or point frequency hopping shielding can be used. 4. For individual minority frequency signal strength ≥ -45dBm, the point frequency hopping shielding method must be adopted. 5. Outdoor equipment is mainly used for large-area shielding of corresponding building units or spaces, and individual leakage points are supplemented by indoor small equipment. d) System implementation method 1. Combining with the actual signal distribution on site, using different combinations of field adjustable frequency band full-scan unit modules, large-area broad-spectrum shielding is performed on frequency bands with general signal strength and more channels. 2. Use the built-in adjustable multi-band module indoor shielding host to supplementally shield the corresponding frequency bands of individual blind spots. 3. According to the different environmental requirements in the prison, scientifically select the directivity and gain of various antennas; at the same time, make full use of the actual building structure, topography and landforms on site, and reasonably choose the erection position, height, and direction. 4. Control the distance between the main radiating surface of the antenna and the place of personnel activities to ensure that the electromagnetic radiation meets the relevant standards. 5. Modular equipment using digital frequency synthesis technology. This technology tracks the frequency of super strong signals in the shielding area and the pilot signal of the channel, so that the mobile phone cannot establish contact with the base station, improving the shielding efficiency, and greatly reducing the intensity of electromagnetic radiation. e) The main equipment requirements of the system 1. The equipment should pass relevant authoritative testing and certification, and it is a mature product with a large number of successful use cases in prisons. 2. The working frequency range of the equipment must be strictly limited to the downlink frequency band, and it is strictly forbidden to cause interference to other systems. 3. The host device must adopt a modular structure to ensure the stable operation of the system and future upgrades. 4. All module power output ports have short circuit and open circuit protection. When the impedance is mismatched, the device can still work normally. 5. The equipment modules are equipped with fault monitoring interfaces. After the fault alarm module is added, fault network monitoring can be realized. f) The system is safe and reliable. 1. There should be no unfavorable components such as plug-in power supplies, external switches, external power tuners, etc. outside the equipment that can be manually shut down or adjusted. 2. The equipment must be able to withstand the need for continuous operation throughout the year in harsh environments. 3. The equipment has strong heat dissipation capacity and can make full use of the natural heat dissipation capacity. During the extreme high temperature period in summer, it can be equipped with a temperature control forced heat dissipation device. 4. Field equipment must have strict field adaptability, and have the capabilities of waterproof, moisture-proof, anti-corrosion, anti-pollution, and lightning protection. 5. All equipment power supplies have protection and self-recovery capabilities such as overload, short circuit, lightning strike, and overvoltage. 6. The life of the equipment itself is not less than five years. g) Equipment and system installation standards 1. The installation height of the equipment must be ≥2m from the ground under the allowable conditions of the construction environment, and the installation must be correct and firm to ensure the normal and stable operation of the equipment; corresponding reinforcement measures must be adopted in the case of poor walls. 2. The installation of outdoor and high-altitude equipment must be able to withstand 11-level wind, and have anti-corrosion, waterproof, and lightning protection measures. 3. Outdoor cable joints must be sealed with one-component room temperature curing silicone rubber for internal sealing, and external pressure-sensitive rubber tape or heat shrinkable tubing for secondary sealing and protection. 4. The cable construction process must meet the requirements of the corresponding technical specifications. 5. When the system is installed, we should try our best not to damage the original building structure, style and decoration requirements while ensuring the technical requirements. We should improve our understanding of the mobile phone shielding system, strictly select product brands and cooperative companies that have completed the shielding project, and carefully organize the installation and commissioning , Dedicated to the best cost-effective shielding project, so that the prison shielding system truly meets the requirements of reliable, accurate, practical, stable and safe use, and provides technical guarantee for the scientific management and harmonious development of the prison.


Free Shipping

Free Shipping

Professional Quality Best Prices

Professional Quality Best Prices

Limited Lifetime Warranty

Limited Lifetime Warranty

100% Secure Checkout

100% Secure Checkout