Identify the features of two way communication

Here we Identify the features of two way communication using two way radio, A two way radio is basically a radio that can transmit and receive. Two way radios are simple, convenient and affordable way to stay in close contact with your colleagues, family and friends. Most companies use two way communication systems as a primary source of communication between their workers due to the ease, promptness and convenience offered by this communication system. The following are some of the key features of a two way radio system and their benefits;

900 MHz frequencies

It is essential to point out that radios that operate within this frequency are capable of effectively communicating both indoors and outdoors. This means that they can be used in factories and other workplaces as well as outside when camping or hiking. Most cordless phones also use this frequency. However, the best thing about two way radios that use the 90 MHz frequencies can be used by both individuals and businesses without a problem.

Adjustable gain

Most two way radios come with an adjustable gain feature. This feature allows the user to adjust the sensitivity of the radio’s microphone. This feature is also useful along with the hands free operation feature because it reduces the possibility of unintended noises triggering transmission. It also enhances the ability of the radio to pick up quite voices.

Auto channel change

This feature enables all radios within your group to change to a new channel. This helps in preventing interference from other devices. For you to use this feature, everyone in your group must have two radios that support this feature. In case one channel is not so clear you can simply change and use the channel with little or no interference.

Backlit display

Most two-way communication devices including radios have a digital LCD display feature that displays useful information for instance your current channel. This feature enables you to turn on a lighted display which makes it easier for you to read the information on the screen especially in dark or poorly lit areas.

Channels

A channel is a frequency on which two individuals using two way radios can communicate. Typically, there are 14 FRS channels as well as 15 GMRS channels. Two way radios that support both FRS (family radio service) and GMRS (general mobile radio service) have the capability of supporting up to 22 channels. This makes it easy for people to communicate with each other using these radios. However, to effectively communicate, all radios in the group should be set to the same channel.

Battery

Two way radios are mobile devices. This means that they are designed for you to move around with them. As a result of this, these radios operate on battery power. Most radios work with standard alkaline AAA or AA batteries. Other models include rechargeable batteries. For those models that come with rechargeable batteries, it is essential for you to always fully charge the batteries before using the radio for effective communication.

Call waiting feature

Just like the regular mobile telephones, two way communication radios also have call waiting feature. If you are already on a call, this feature allows you to receive a notification that someone is attempting to reach you. The latest models will give you an option of immediately accepting the new incoming call or simply reject the call and calling back thereafter.

Call tones

Call tones allows the user to alert the other radio users in the group that he or she wants to talk. It is similar to a telephone’s ringing that indicates that someone wants to talk or someone is calling. Most radios allow the user to select from a variety of call tones.

Intrinsically safe

Also known as IS, intrinsically feature is a protection feature or technique used for safe operation of electronic devices in explosive environments. This concept was solely developed for safety measures specifically operation of process control instrumentation in unsafe areas. This means that two way communication radios can be safely used in hazardous areas without the fear of exploding or causing harm to the user.

In summary, from the above features and benefits of two way communication radios it is clear to suggest that, these radios are convenient, affordable and safe modes of communication that can be used in workplaces as well as at home. They can also be used outdoors during camping, hiking or simply enjoying a shopping expedition in town.

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Hytera explosion-proof two-way radios vital for oil & gas sector safety

Hytera, the world’s leading professional mobile radio communications solution provider, has announced its first-time participation at this year’s edition of Saudi Safety and Security, Saudi Arabia’s leading security, fire and safety conference and exhibition, which will be held on May 10-12, 2015 at the Dhahran International Exhibitions Centre (DIEC) in Dammam.

During the exciting three-day show, the company is expected to highlight the importance of using explosion-proof rated digital two-way radios across key industry verticals, particularly for the oil gas segment. The PT790EX, a TETRA radio that is compliant with the world’s most stringent explosion-proof certification, will be pre-launched at the show and will be made available in the Saudi market later this year.

Hytera understands the challenge of professionals working in highly-hazardous environments especially those operating in oil gas facilities. To address this issue, the company has developed a strategic range of intrinsically safe and reliable communications solutions that conform to international digital radio safety standards. Hytera offers a full line of explosion-proof two-way radios, following two mainstream technologies, namely Digital Mobile Radio (DMR) and Terrestrial Trunked Radio (TETRA), which includes the PD795 EX, PD785(UL913), PD705(UL913), X1p(UL913), PT580H(UL913) and the PT790EX. The units have been specifically designed for use in environments with explosive gas and combustible dusts, where using regular radios could be unsafe. Presented in a rugged and ergonomic-friendly design, the units present key features like easy operability, long battery life and in compliance with set international standards for safety and security. Features like man-down and lone-worker goes extra miles to offer great assurance for personnel working in remote or isolated conditions.

“We are looking forward to our first time participation at this year’s Saudi Safety and Security 2015, which will allow us a strategic platform to leverage our diverse range of radio transceivers and radio systems across the Kingdom’s various industry verticals, particularly in the oil gas industry. In addition, our presence at the show will also afford us the advantage of reaching out to more potential users—telling them of the many advantages and benefits to be gained from using our products. We are excited to meet new contacts and enter into potential opportunities. The Kingdom represents a wide gamut of possibilities for us and we are now also looking to open an office here to further reinforce our leadership in the market. In fact, there are already more than 10,000 Hytera digital radios in use in the Kingdom today,” Dawud Liu, Sales Manager for KSA, Hytera.

Established in 1993 in Shenzhen, China, Hytera operates on a global basis and develops radio systems and solutions that are in compliance with set international standards like DMR, TETRA and MPT-1327. The company offers a wide portfolio of customized communication solutions to government, public security, utility, transportation, enterprise business for higher organizational efficiency.

To date, Hytera has established a global sales network with more than 20 subsidiaries and offices in USA, UK, Germany, Australia, Brazil, etc. and ensures around 15% of revenue for RD to keep pushing the limit leading and mature technologies. Hytera’s five RD facilities are located in Shenzhen, Harbin and Nanjing in China and Hannover and Flensburg in Germany have created a state-of-the-art platform for digital technology research, product design and application development. — SG

As you can see on this Article Hytera really are making strides in this area, the famous Intrinsically safe radios are being surpassed by a new brand of safety. Hopefully the explosion-proof element of the radio won’t need to be proven, but this is an exciting Element.

Digital radio – which way will South Africa go?

Radio technology has seen very little innovation and development since FM stereo was introduced in the 1960s.  It was the sound revolution of the time, but little has happened since FM took over local broadcasting. It caused the demise of AM stations and the shortwave services of the SABC and LM radio.

The Southern Africa Digital Broadcasting Association (SADIBA) issued a report in 2002 in which it said “to remain commercial attractive, radio as a medium will have to deliver improved quality service, greater choice, interactivity and multi-media. Digital radio technologies must rise to the challenge and deliver the multimedia radio of the future.”

In the document SADIBA made recommendations on the critical aspects to be considered in order to allow for the introduction of digital radio in South Africa.   Little seems to have happened since 2002 until last month when the subject was extensively discussed at the SADIBA Conference where the 2002 paper re-emerged and digital radio mondiale (DRM), one of the technologies, came into the limelight with international speakers and a demonstration of DRM by the BBC transmitting DRM from their  shortwave relay station on Ascension Island with CD clarity – no noise, no interference.

Discussing the advantages of DRM, Ruxandra Obreja, head of digital radio development at the BBC world service and chairman of the DRM Consortium said that DRM and DRM+ have proved to be the obvious choice for digital radio. But not everyone would agree with that.

Let us consider some of the various digital radio technologies available.

IDAB is based on in-band-on channel (IBOC) technology which looks at inserting the digital signal within the existing FM and AM channels without affecting other FM or AM transmissions.  FM IBOC is designed to operate in a 200 kHz FM channel allocation. It would have been very impractical to introduce FM IBOC into South Africa without re-engineering the current  FM frequency plan based on 100 kHz channel.

According to the 2002 SADIBA paper the most established of all the digital radio technologies is the Eureka 147 system.  The technology is based on an open standard defined in a range of the European Telecommunications Standards Institute (ETSI) documents. But it requires different frequency bands which in itself is problematic given the scarcity of spectrum oin the UHF bands which are demanded by satellite communication channels (VSat) and wireless broadband. The so-called digital dividend will also not provide the required spectrum as that process will take a long time to materialise.

Obreja believes that DRM and DRM+ is the obvious solution. DRM,  the acronym for digital radio mondiale, is promoted by a consortium of broadcasters, manufactures’ research institutes and stakeholders that have endeavoured to work toward a world-standard for digital broadcasting in the frequencies initial below 30 MHz, operating on the AM and shortwave broadcasting bands.  Since the original development engineers have moved ahead and DRM+ emerged, the name applied to the DRM standard when used on the VHF frequencies.

“The initiative to extend DRM began with a vote at the 2005 General Assembly to begin the design, verification and testing of the parameters needed to allow DRM to operate in the VHF broadcasting bands between; primarily band I and band II,” said Obteja.

The design process began shortly afterwards and key decisions were made to ensure that the extension completely shared the successful design philosophy of DRM – it is “DRM but at higher frequencies”.

Its spectrum usage parameters are determined from the internationally agreed norms in the FM band (88 to 108 MHz). Therefore it has an occupied bandwidth of 96 kHz and a frequency grid of 100 kHz.

DRM+ provides bit rates from 35 kbps to 185 kbps at SNRs from 2 dB to 14dB and, like DRM, permits up to four services. It is therefore a flexible solution allowing single or small numbers of audio services to be broadcast together.

During the process of gaining endorsement from the ITU for DRM’s extension to the VHF bands, test results from various field trials conducted around the world were submitted.  One of the interesting trials was carried out in December 2011 by Vatican Radio carrying out broadcasting tests of DRM+1 in the VHF band II at 103, MHz. The aim of the tests was to verify the performance of DRM+ in a difficult interference scenario such as the FM VHF band II in Rome and to check the compatibility of the digital technology with existing antenna arrays having complex RF coupling systems such as the one located in the Vatican. The frequency used was assigned to the Vatican in the GE84 Agreement and was chosen for two main reasons: it is not used during a few timeslots in the morning and it suffers from some strong interference coming from stations operating at 103,7 MHz and 104,00 MHz located close to Rome. The tests were carried out taking into account the normal programme schedule. During the tests the digital transmitter was connected to the antenna feeder via a changeover, leaving the analogue transmitter in stand-by. The antenna array is a complex system: four FM transmitters at different power levels share the same antenna with elliptical polarisation and omni-directional horizontal radiation pattern. The results were great. Acceptable stereo coverage under mobile reception conditions has been verified in areas where predicted field strength is comparable with 44 dBmV/m and interference is negligible. Using the most robust configuration for DRM+, it was possible to achieve better coverage in full stereo  than an analogue FM signal; the overall subjective listening experience was better than that of FM interfered with by splashes coming from adjacent stations.

With South Africa’s poor performance in changing from analogue to digital TV, it may be some time before government will applies its mind to take a decision on digital sound radio. The first step have however been taken by commercial enterprises.  Pulpit Radio is conducting a DRM pilot from their transmitting station  at  Kameeldrift near Pretoria. The 50 kW transmitter was installed by Broadcom International and made history with the first DRM audio broadcast in the Southern African region on 1440 kHz AM. “The results were very good. The station was received in Botswane some 400 km away with CD quality audio,” Obreja said.

One of the issue is however the availability of receivers but Ruxandra Obreja said that experience from elsewhere where DRM was introduced local industry began manufacturing. “This will be a great opportunity to grow South Africa’s electronic manufacturing industry.”

There is software available to decode the DRM signals using a sound card and a dongle is under development that can be used on a laptop or even other devices that have a USB port.

With DRM, the use of medium and shortwave will open up many new radio channels. Each DRM channel can carry three radio programmes and one data channel requiring very narrow bandwidth of less than 5 kHz. Another advantage is that the system is also more energy efficient.

It is very true that we’ve not seen much innovation in the two way radio industry, Here we have seen the Digital revolution in the past few years, but it is far more complex in Africa. Larger coverage area and less technological advancement. You can find the original news story on this website.