STJグループ（株式会社サンテレコムジャパン、株式会社STJレンテック） List of Products and Services

Wireless radios are an essential tool for communication at events and construction sites, but have you ever felt dissatisfied with the communication range or quality? In such cases, we recommend IP radios and IP radio apps. In this article, we will introduce the differences between IP radios and mobile phones/smartphones, as well as the features, benefits, and usage of IP radio apps. Please take a look for reference. *You can view the detailed content of the article through the related links. For more information, please feel free to contact us.*

• Radios, walkie-talkies, and intercoms

IP radios are wireless devices that use mobile phone communication networks or internet connections to make calls. Unlike conventional radios, they do not require a license or registration, making them easy to use. Additionally, they allow for nationwide communication in Japan, and since the call charges are flat-rate, costs can be kept low. This page will explain the communication mechanism of IP radios, their types, advantages, disadvantages, recommended models, and usage examples. *For detailed content of the article, please refer to the related links. For more information, feel free to contact us.*

• Radios, walkie-talkies, and intercoms

The season for shareholder meetings, exhibitions, and events is approaching, but are you ready with your radios? Radios are essential for smooth operations and trouble response, but with so many types available, some may be unsure about which to choose. This time, we will focus on shareholder meetings and introduce the models that received particularly positive feedback from those who have actually used rental radios. *For more detailed information, please refer to the related links. Feel free to contact us for more details.

• Radios, walkie-talkies, and intercoms

Summer is just around the corner, and behind the bustling fireworks festivals where many people gather, various stakeholders are collaborating to manage the event. At the heart of this operation are radios and transceivers. These tools are essential for improving the efficiency of event management by allowing instant communication. On this page, we will explain how radios and transceivers are used in the management of fireworks festivals based on past usage records, and which types of radios are most suitable. *For more detailed information, please refer to the related links. Feel free to contact us for further inquiries.*

• Radios, walkie-talkies, and intercoms

The importance of communication is increasingly rising, and radios, transceivers, and intercoms (hereafter referred to as radios) are essential tools in modern business. Even though there are many types of radios, you may come across unfamiliar terms, or you might have a general understanding but lack detailed knowledge, which is quite common. This glossary has been created to explain the complex words and concepts related to radio communication in a simple and clear manner. It summarizes the terms related to the types, management, and operation of radios, and I hope it will be helpful to you. *For detailed content of the article, you can view it through the related links. Please feel free to contact us for more information.*

• Radios, walkie-talkies, and intercoms

Smartphones and mobile phones have become indispensable tools in business. However, there are many specialized terms that are emerging, and while we may have a general understanding of their nuances, we often do not know their true meanings. This smartphone glossary primarily picks up and lists terms that you might hesitate to ask someone about or that are not widely recognized. When introducing smartphones, there are several points to consider, such as security measures and app selection. We hope that this glossary will assist you in the introduction and operation of your smartphones. *You can view the detailed content of the article through the related links. For more information, please feel free to contact us.*

• Mobile phones and smartphones

The premium internet service provided by "USEN GATE 02" is an ultra-fast internet service with speeds of up to 10Gbps. Unlike shared fiber optics used by multiple users, the premium internet offers a dedicated line service that provides a direct fiber optic connection to each customer, ensuring stable communication. By using a dedicated line, the service is less affected by other users, resulting in stable communication and the ability to create a comfortable internet environment. 【For those with the following concerns】 ■ Haven't reviewed the network in a long time ■ Increased web meetings compared to before ■ Complaints about slow internet from within the company ■ Recently implemented remote work ■ Actively using cloud services *For more details, please refer to the related links or feel free to contact us.

• Wi-Fi router

"STJ Rental Wi-Fi 100" is a corporate cloud Wi-Fi service that automatically connects to the most suitable network among the three major mobile carriers. It can be used immediately when needed, with the fastest shipping available on the same day after application. Once it arrives, you can start using it right away. Short-term rentals are available from one month, and with our service, you can contract for only the necessary period to keep costs down. 【Features】 ■ Reliable connectivity with cloud Wi-Fi ■ Automatically connects to the most suitable network among the three major mobile carriers ■ Ideal for spot usage, ready to use when needed ■ Rental available from one month ■ Simple and straightforward plan *For more details, please download the PDF or feel free to contact us.

• Wi-Fi router

Points will be awarded based on the monthly usage fee and communication charges for the eligible KDDI fixed communication services associated with au mobile phones. Corporate customers tend to accumulate points easily due to multiple contracts, but they often have little awareness of how many points they have. Upon checking, they usually find that they have accumulated a significant amount. Since corporate customers have fewer opportunities to use their points, it is not uncommon for points to expire. *For more details on the column, please refer to the related links. For further inquiries, feel free to contact us.

• Mobile phones and smartphones

Frequent iOS updates occur while using an iPhone. It is important to update to the latest software, but many people have questions like, "What exactly is an update?" and "What happens if I skip an update?" Therefore, this time, in addition to the basics of iPhone updates, we will also explain the impact of skipping updates. *For more detailed information, you can view it through the related links. Please feel free to contact us for more details.*

• Mobile phones and smartphones

One of the common challenges in the operation of business smartphones is the management, sharing, and backup of contact data. In this article, we will introduce a cloud contact management service that allows for easy management, sharing, and backup of customer and employee contact information registered on smartphones. If you are experiencing challenges with managing and sharing contact information on business smartphones, please take a look. *You can view the detailed content of the column through the related links. For more information, feel free to contact us.

• Mobile phones and smartphones

Many people are preparing for disasters. Communication disruptions are one type of disaster. In this column, we will introduce methods to prepare for communication disruptions, specifically DSDS (Dual SIM Dual Standby) and secondary line services. When a communication disruption occurs suddenly, important data may become impossible to send or receive, and systems may come to a halt. Are you fully prepared for such situations? One way to prepare for such circumstances is through communication redundancy. *For more details on the column, you can view it through the related links. Please feel free to contact us for more information.*

• Mobile phones and smartphones

Unlike mobile phones, radios (transceivers) that allow for group communication with a single button are invaluable in various situations. Just by having a radio, information can be shared quickly at any time, and its broadcast capability and immediacy greatly contribute to improving work efficiency. There are various types of radios, but one that has recently gained attention is the IP radio application that utilizes mobile phone network communication areas. In this article, we will introduce the types and features of conventional radios, compare conventional radios with IP radio applications, highlight the unique features of IP radio applications, provide case studies, and finally introduce the IP radio applications we offer. *For detailed content of the column, please refer to the related links. For more information, feel free to contact us.

• Mobile phones and smartphones

MDM (Mobile Device Management) is effective for managing and monitoring corporate smartphones and mobile phones. This time, we will introduce "Restrictions," which is suitable for managing iOS devices, as one of the main features of MDM. "Restrictions" help unify the operational policies of corporate smartphones, enhance security, and prevent personal use. In this article, we will explain why to use restrictions with MDM and how different users can comfortably utilize them. Please be sure to read until the end. *For detailed content of the column, you can view it through the related links. For more information, please feel free to contact us.

• Mobile phones and smartphones

"LINE WORKS" is a business chat tool that can be used with peace of mind for work. It allows communication not only among company members but also with clients and customers, and you can interact with customers who do not use this service via LINE. With a familiar interface and features, anyone can start chatting right away, and with over 1,000 types of rich stickers, feelings can be conveyed even in business. The read confirmation feature allows you to check which members have read or not read the messages. [Features] - Account management is secure - Communication is possible with stickers and short messages - The read function allows you to see who has viewed the messages *For more details, please refer to the PDF document or feel free to contact us.

• Mobile phones and smartphones

"KDDI SMART Address Book" is a business-oriented cloud address book service that can be used from smartphones and PCs. It is specifically designed for business use, offering robust features for administrators such as permission settings, access restrictions, and bulk import functionality for address books. It can be used on PCs and smartphones, allowing users to switch between devices according to their usage scenarios. 【Features】 ■ Address book sharing ■ Comprehensive features to reduce management burden ■ Available on multiple devices *For more details, please refer to the PDF document or feel free to contact us.

• Mobile phones and smartphones

"STJ Fault Support (i) 1 Year" is a corporate mobile phone and smartphone insurance that fully covers repair costs for smartphone accidents such as water damage, breakage, and malfunction. *Devices purchased from Santelecom Japan are eligible for coverage. It provides coverage for repair costs due to malfunction, breakage, or water damage for iOS devices (iPhone, iPad) up to twice a year. With a contract for Santelecom Japan's BPO services, you can rest assured during the repair process. The repaired items will be ready for immediate use upon delivery. 【Features】 ■ Repaired items are returned after kitting ■ Custom repair flow construction for your company is possible ■ Management can be centralized even if the contracted communication providers are different ■ Covers water damage, breakage, and malfunction *For more details, please refer to the PDF document or feel free to contact us.

• Mobile phones and smartphones

Santelecom Japan, as a top-class agency in KDDI's Kanto corporate sales division, has dedicated representatives who will provide clear and courteous assistance even to first-time customers. A corporate contract refers to applying for a contract under the name of a corporation, such as a stock company or a limited company. Our company offers "special corporate prices" for all scenarios including "new contracts," "device changes," and "switching from other companies." 【Benefits】 ■ Reduction of communication costs such as calls and internet ■ Improved business efficiency with suitable options and plans ■ Centralized management of employee mobile data ■ Increased employee satisfaction *For more details, please refer to the PDF document or feel free to contact us.

• Mobile phones and smartphones

To the members of the School Festival Executive Committee, we would like to introduce a case study involving the "radio equipment" that our company handles. Typically, we communicate via phone or LINE, but it often takes time for information to reach everyone, and there have been many instances where we couldn't contact each other when urgent matters arose. Therefore, we proposed the high-end model "MiT3000," which prioritizes ease of use. With radio equipment, it is possible to send messages to all radios on the same channel simultaneously. [Case Overview (Partial)] - Industry: Students (School Festival Executive Committee) - Manufacturer: Motorola Solutions, Inc. - Model Introduced: Portable Digital Simple Business Radio "MiT3000" - Number of Units Introduced: 55 units *For more details, please refer to the PDF document or feel free to contact us.

• Radios, walkie-talkies, and intercoms

To our customers in the electrical equipment sector, we would like to introduce a case study involving the implementation of the "radio equipment" we handle. Previously, they were using analog radios, but one unit was damaged, and since repair was not possible, they expressed a desire to introduce new radio equipment. In response, we proposed the reliable, high-quality digital radio "MiT5000" for their challenging work environment. As a result of the implementation, the use of a dual-microphone noise-canceling feature led to clearer voice communication with less noise, thereby increasing efficiency during operations. 【Case Overview (Partial)】 ■Industry: Electrical Equipment ■Adopted Manufacturer: Motorola Solutions, Inc. ■Model Introduced: Portable Digital Simple Business Radio "MiT5000" ■Number of Units Introduced: 10 units *For more details, please refer to the PDF document or feel free to contact us.

• Radios, walkie-talkies, and intercoms

IP radios have increasingly been used in various situations. The demand for rentals is also growing year by year. In this context, a new model "SRNX1" has been introduced by Yaemura Radio for IP radio rentals. In this article, we will review the basic knowledge of IP radios, introduce the features of the SRNX1, and recommend ways to use it. *For detailed content of the column, please refer to the related links. For more information, please check the PDF materials or feel free to contact us.

• Radios, walkie-talkies, and intercoms

The "SRNX1" is an IP radio that uses wide-area LTE networks. It not only possesses the broadcasting capability and immediacy of conventional radios, but also features high waterproof and dustproof performance, as well as a battery that can withstand long hours of use. It pursues high visibility screens and simple operation methods, catering to professional needs. 【Features】 ■ Uses LTE networks to cover all of Japan ■ Sturdy body with loud volume ■ Easy to check at a glance and one-touch operation *For more details, please refer to the PDF document or feel free to contact us.

• Radios, walkie-talkies, and intercoms

The "IC-DU75 PLUS" is a radio equipped with a recording function that allows for the review of call content, compatible with amplification. It also features a sub-channel PTT function that enables transmission and reception across up to three channels without the need to switch channels. This device can efficiently cover multiple instruction and communication systems with a single radio, and it allows for simultaneous monitoring of three channels. 【Features】 ■ Sub-channel PTT function covering up to three channels ■ Automatic channel switching for relay station areas ■ Implementation of a Bluetooth receiver compatible with data and voice communication ■ High operability ■ Various functions to prevent missing important communications *For more details, please refer to the PDF document or feel free to contact us.

• Radios, walkie-talkies, and intercoms

The "SR510" is a compact, rugged, and clear communication-capable radio that supports amplification. It features a dual-microphone noise cancellation system that ensures clear communication even in loud environments. With a robust design, it offers high reliability and is rated IP68 for top-class dust and water resistance. 【Features】 - Equipped with 82 channels of digital simple radio (registered station) - Professional-grade basic performance in a small size - Easy operation that anyone can use - Lightweight and compact with over 13 hours of battery life - Supports business communication with a variety of functions *For more details, please refer to the PDF document or feel free to contact us.

• Radios, walkie-talkies, and intercoms

The SR741 is a wave-enhancing radio equipped with professional-grade basic performance and reliability, along with a variety of features to support on-site operations. It boasts top-class dust and water resistance with an IP68 rating, allowing for safe use even in rainy conditions or dusty construction sites. Various functions, such as the quick answer feature and vibrator incoming call function, support smooth business communication. 【Features】 - Equipped with 82 channels of digital simple radio (registered station) - Ensures reliable communication even in loud noise or strong winds - High-quality sound and loud volume at 800mW - Lightweight and compact with over 16 hours of battery life - Top-class dust and water resistance (IP68) *For more details, please refer to the PDF document or feel free to contact us.

• Radios, walkie-talkies, and intercoms

The "SR810UA/SR820U" is a compact, rugged, professional-grade radio that boasts excellent basic performance and reliability, designed for amplification support. It features top-class dust and water resistance (IP68) and employs the expertise of communication equipment manufacturers, with a robust internal structure carefully crafted down to each individual component. Additionally, it is equipped with user-friendly original features such as multi-channel standby functionality and CUE (cue) function for emergency notifications. 【Features】 ■ Lightweight and compact ■ 5W high output, wide communication area ■ Dust and water resistant (IP68) ■ Noise cancellation function ■ 16 hours of operation, long battery life *For more details, please refer to the PDF document or feel free to contact us.

• Radios, walkie-talkies, and intercoms

The "TPZ-D561/TPZ-D561BT" is a slim-designed, wave-enhancing wireless device that features antibacterial and antiviral processing. This transceiver can be used without qualifications and is equipped with the convenience of a "clear hearing mode" for clear communication even in noisy environments, as well as the option for a Bluetooth-compatible model. With a robust design that is dustproof and waterproof (IP68), it can be safely used in any environment. 【Features】 ■ Safe for shared or rental operations ■ Compact design that is easy to hold and convenient to carry ■ "Clear hearing mode" that makes voices easy to understand even in noisy conditions, and also makes voices easier to hear through masks ■ Second PTT function that works as two units with just one device *For more details, please refer to the related links or feel free to contact us.

• Radios, walkie-talkies, and intercoms

The "TCP-D261E/D261BTE" is a booster-compatible wireless device that can be used stress-free even in multi-channel environments thanks to its high-speed scanning. By adopting the optional repeater "TCB-D239CR," the communication area is significantly expanded, allowing for calls in traditionally dead zones such as mountainous areas separated by hills and urban areas with tall buildings. No qualifications are required, and you can easily start powerful communication with just a license application. 【Features】 ■ Compact design for easy portability ■ Convenient Bluetooth functionality (TCP-D261BTE only) ■ "Clear Listening Mode" for better voice clarity in noisy environments ■ Second PTT function that works as two units in one ■ Zone settings for smooth compatibility with different channels *For more details, please refer to the PDF document or feel free to contact us.

• Radios, walkie-talkies, and intercoms

MDM (Mobile Device Management) is effective for managing and monitoring corporate smartphones and mobile phones. In addition to device management and security enhancement, MDM has convenient features, among which the "app distribution feature" is very helpful for improving the operational efficiency of corporate smartphones and preventing personal use. In this article, we will explain the "app distribution feature" of MDM and introduce the convenient feature "App Catalog" of our MDM product, 'OptimalBiz.' *For detailed content of the column, you can view it from the related links. For more information, please refer to the PDF materials or feel free to contact us.

• Mobile phones and smartphones

This page introduces "Apple Business Manager" (hereinafter referred to as "ABM"), which is essential for managing iOS and iPadOS devices. ABM is a program provided by Apple for businesses that supports the realization of more advanced device management by integrating with "MDM tools," which is a collective term for automatic device enrollment and bulk app distribution. There is no cost involved. *For detailed information in the column, you can view it through the related links. For more details, please refer to the PDF materials or feel free to contact us.

• Mobile phones and smartphones
• Other Software

To efficiently manage and secure mobile devices necessary for business, the MDM solution is recommended. MDM refers to services or software that centrally monitor and manage mobile devices. In this article, we will clearly explain the necessity, functions, and implementation points of MDM. *For detailed content of the column, please refer to the related links. For more information, please check the PDF materials or feel free to contact us.*

• Mobile phones and smartphones

MDM "OPTiM Biz" is an MDM developed by Optim Corporation and supports multi-device management. MDM (Mobile Device Management) is a system designed to efficiently manage mobile devices such as smartphones and tablets, enhancing security. Implementing MDM in the operation of smart devices within a company is a crucial point for preventing information leaks. 【Features】 - No server setup required - Centralized management of devices - Multi-device support - Device locking in case of loss or theft - Automatic checks for security violations - Restrictions on non-business applications *For more details, please refer to the PDF document or feel free to contact us.

• Mobile phones and smartphones

In recent years, many companies have been introducing corporate smartphones and mobile phones to improve business efficiency and enhance security. However, there are likely many personnel who struggle with the kitting process even after the devices are introduced. Therefore, this time, we will introduce the reasons why kitting for corporate smartphones and mobile phones can be challenging, as well as key points to proceed smoothly. *For detailed content of the column, you can view it through the related link. For more information, please refer to the PDF document or feel free to contact us.*

• Mobile phones and smartphones

We would like to introduce our "BPO Services." We solve issues related to mobile phones that contain important customer information, such as "I implemented MDM but can't use it effectively" or "I don't know what to do when my smartphone breaks." MDM can be managed collectively by our company. Additionally, in case of a malfunction, we can promptly arrange for smartphones and tablets. Remote locking and unlocking of mobile phones is also possible. 【Scope of Services】 ■ Application reception desk ■ Device arrangement ■ Kitting ■ Inquiries and maintenance ■ Device management ■ Aftercare *For more details, please refer to the PDF document or feel free to contact us.

• Mobile phones and smartphones

Recently, many companies have been incorporating BPO and outsourcing as important elements in their management strategies. While the term "BPO" is known, it seems that there are still few people who accurately understand its specific content. In this article, we will explain the overview of BPO in detail, discuss its advantages and disadvantages, and also introduce BPO in the management and operation of company smartphones. *For detailed content of the column, you can view it through the related links. For more information, please refer to the PDF materials or feel free to contact us.

• Mobile phones and smartphones

"Marumo" (Comprehensive Mobile Business Support Service) is a unique BPO service from Santelecom Japan. It makes managing corporate mobile phones and smartphones much easier. It provides strong support for security enhancements and in case of loss. We offer operational support for BPO services aimed at corporate mobile phones. Dedicated staff will respond quickly, no matter where you are in the country. [Features] - Support via a free call number (incoming calls only) and a dedicated email address - Bulk management and operation with dedicated software - iOS repairs are also supported - Nationwide service - Consistent support from dedicated staff - Same-day response for lost devices *For more details, please refer to the PDF document or feel free to contact us.

• Mobile phones and smartphones

The "TPZ-D563E/TPZ-D563BTE" is a high-power digital transceiver that supports 82 channels and excels in resolving interference issues. Additionally, it is compatible with 15 channels dedicated to receiving in the upper air, bringing the total to 97 channels. The recommended data channels are suggested for use with status updates and short messages. 【Features】 ■ Supports channel amplification ■ Stress-free high-speed scanning ■ Compact design for comfortable portability ■ Convenient Bluetooth functionality ■ "Clear Listening Mode" for easy comprehension even in noisy environments ■ Second PTT function that works as two units with just one device *For more details, please refer to the related links or feel free to contact us.

• Radios, walkie-talkies, and intercoms

The "IC-D70 PLUS/IC-D70BT PLUS" is a digital simple radio that can be used with just registration. In 2023, it supports the expansion of digital radios (DCR) announced by the Ministry of Internal Affairs and Communications to 97 channels. This allows users to be free from interference due to a lack of channels, enabling more comfortable operation. 【Main Features】 ■ Supports channel expansion from 35ch to 97ch ■ Sub-channel PTT function covering up to 3 channels ■ Automatic channel switching for relay station areas ■ Equipped with Bluetooth receiver and vibration function ■ High operability ■ Various functions to prevent missing important communications *For more details, please refer to the related links or feel free to contact us.

• Radios, walkie-talkies, and intercoms

The "SR730/SR740" is a professional-grade communication device from STR, boasting excellent basic performance and reliability in a compact and rugged design. It features top-class dust and water resistance with an IP68 rating, making it safe to use even in rainy conditions or dusty construction sites. Additionally, even when the battery and antenna are removed, the main unit and battery alone maintain an IPX8 waterproof rating, allowing for worry-free use in environments where battery replacement is necessary during rain. 【Features】 ■ No qualifications required ■ Lightweight and compact ■ 5W high output for a wide communication area ■ Dust and water resistant (IP68) ■ Noise cancellation function ■ 16 hours of operation with long battery life *For more details, please refer to the related links or feel free to contact us.

• Radios, walkie-talkies, and intercoms

This article explains the amendments made in the fiscal year 2023 regarding the increase in power for digital simple radio stations. The purpose of the power increase is to alleviate areas where radio waves were congested and difficult to use due to location and time. It also explains precautions when using the increased power simple radio. *For detailed content of the article, you can view it through the related links. Please feel free to contact us for more information.

• Radios, walkie-talkies, and intercoms

Our company offers a range of "Portable Digital Transceivers" that comply with the "Increased Power for Digital Simple Radio Stations" announced in 2023. By reducing the risk of interference due to location and time, we can achieve stable communication through the elimination of dead zones and improvement of communication sound quality. We not only propose radios that meet your needs but also provide support for on-site surveys and application assistance for licenses and registrations. Please feel free to contact us. 【Product Lineup】 ＜iCOM "IC-D70 PLUS" "IC-D70BT PLUS"＞ ■ Equipped with a recording function to verify call content ■ Supports automatic channel switching for relay station areas ＜KENWOOD "TPZ-D563BTE" "TPZ-D563E"＞ ■ Can be used without qualifications with simple registration ■ Features a "Clear Listening Mode" that is resistant to noise ＜Yaesu "SR730" "SR740"＞ ■ Capable of operation for up to approximately 16 hours with a large-capacity battery ■ Equipped with a multi-channel standby function *For more details, please refer to the materials. Feel free to contact us with any inquiries.

• Radios, walkie-talkies, and intercoms

We would like to introduce our digital radio, the 'MiT5000'. This product is a licensed transceiver that contributes to the formulation of BCP (Business Continuity Plan) in care facilities and ensures the safety of users. It minimizes the impact between radios used in urban areas. It accelerates information sharing during emergencies and promotes appropriate responses. By strengthening collaboration among staff, it contributes to ensuring the safety of users. 【Features】 ■ Usable during power outages ■ Wide-range communication ■ Strengthened collaboration among staff ■ Ensured safety of users ■ Enhanced BCP formulation ■ Easy operation *For more details, please refer to the related links or feel free to contact us.

• Radios, walkie-talkies, and intercoms

We would like to introduce our IP radio, the 'TLK100'. This product is cordless with Bluetooth earphones, allowing for efficient movement without being hindered by long cords. Charging is done using a USB cable, so no dedicated charger is required. Additionally, it is lighter and thinner than typical radios, reducing the burden on your waist. 【Features】 ■ Cordless with Bluetooth earphones ■ Clean hand microphone with Bluetooth ■ Lighter and thinner than typical radios ■ Usable anywhere within the area *For more details, please refer to the related links or feel free to contact us.

• Radios, walkie-talkies, and intercoms

In recent years, the demand for business radios has increased as part of efforts to improve work efficiency and safety measures in the industrial sector. Radios equipped with explosion-proof features and approved by licensed stations are being used safely. This article explains how to utilize the rental of business explosion-proof radios. *For detailed content of the column, please refer to the related links. For more information, feel free to contact us.

• Radios, walkie-talkies, and intercoms

Explosion-proof radios are designed with a special structure to ensure that they do not become an ignition source for fires or explosions when flammable gases, vapors, or dust are released into the atmosphere. These radios have passed explosion-proof standard inspections conducted by certification bodies and have received certification. They are commonly used in various factories, industrial complexes, and chemical plants. In this column, we will explain in detail what explosion-proof means and why it is necessary, starting from the basic knowledge. *For more details on the column, you can view it through the related links. Please feel free to contact us for more information.*

• Radios, walkie-talkies, and intercoms