Nowadays, almost every of us carry one or more cell phone to network with others in all walks of life. However there is a fact that not everywhere we go covers cellular signal or good quality signal, especially in some office building, warehouse, rural areas, etc. It can be very frustrating and cause huge inconvenience for people living or work there. To tackle these blind spots, operators or some enterprises will take repeater as an economical option to extend/improve the coverage.
Here comes the problem: how to customize a suitable repeater for different scenarios?
China has been a fast learner and developer in manufacturing repeater for cellular/trunked radio communication. The price can also vary much based on the material, quality, technology, craftsmanship… It won’t be surprise to find a great number of low end suppliers: cheap price and un-incredible speed of delivery, even free shipping. But if you are an expert in telecommunication and know well how to customize the proper repeater for every project, you definitely won’t miss excellent suppliers like ACTION amid the ocean of repeater supply.
This is how an expert will consider before customizing a repeater:
1. Confirm the SCENARIO / APPLICATION
Places that are often out of service or without service, and particularly of high demand will be considered to deploy cellular coverage. Provided there is village far beyond the downtown and home at the middle of mountains, building a BTS will be the first and best choice. For repeater only functions as the re-transmitter, it adapts to areas that can receive signal from the BTS, then manage to enhance the coverage to the signal-poor areas. Let say buildings, underground, basement, board ship and so on.
According to various applications, repeater can be categorized into indoor and outdoor usage. Indoor type of repeater will be deployed much in rooms, where 15-27dBm output power would be enough to fulfill the needs in such a narrow space. Outdoor type of repeater will be installed in open and larger areas, for the signal required to transmit to farther space and meet more demands. By this time, output power can raise to 27-43dBm. Whereas, the category is not absolute: outdoor type of repeater can be used in indoor applications when the signal from the BTS is too weak to capture. Better details the scenario with engineer to analysis during customization.
2. Find out the CAUSE OF NO SIGNAL
A simple way to check whether your network service is good or not, is too see the bars on your cell phone. Do you know that the bars can tell you more than the signal strength? It indicates both the signal strength and signal quality, which means your distance to the BTS, as well as the noise and interference surround you might prevent you from enjoying a faster and smoother surfing experience.
Go check out the BTS around you. If you find yourself thousands of miles away from the nearest tower, you highly possible have no service on your phone. As we will get exhausted after finishing a marathon, signal will attenuate through the air until reaching your phone. But after a long travel, there will be not much left for you. If you find yourself at the middle of two or more BTS and all are close, you phone can be very charming as the BTS will compete for serving you. This can be trouble as signal from the other BTS will turn out to be interference to you phone. You will get poor signal rather than strong signal under the circumstance.
Second, check out the environment. Staying in a well-built architecture, elevator, depth of underground, peak of a mountain can stop the signal from accessing your phone. Signal will decay through all kinds of materials, which is a matter of media.
Third, check out the frequency. If you phone always lingers at 2G signal and few 4G signal, it can be the frequency problem. Higher frequency will suffer harder attenuation than the lower frequency. Following the principle of survival of the fittest, don’t blame your phone for choosing the 2G now; get yourself a 4G repeater.
3. Figure out the SYSTEM & FREQUENCY you want
Most of the time we come across to frequency range / band like 900MHz, 1800MHz, 2100MHz, 2600MHz, etc. But note that country will allocate frequency range for different cellular technology on its own; later operators will bid for the section for commercial deployment. A 900MHz frequency can be a GSM900, EGSM900, WCDMA/UMTS900, or LTE900. Usually countries will not use the same range as another country. After operators win their sections, a GSM900 band can specify as 880-915MHz/925-960MHz, or 880-915MHz/925-960MHz.
Determine the system and frequency of a repeater is of huge significance. Repeater will be equipped with filter to regulate the working frequency for normal running. A little bit wider is alright as the bandwidth is able to cover, while narrow than the working bandwidth is 100% not working, for it will cut some channels out of the service. One should be very careful of the frequency details.
4. Choose the right ANTENNA
A RF repeater is working with an antenna to realize the final coverage. There usually are two main ports in the repeater: BS (Base Station) and MS (Mobile Station). They are used to distinguish the input and output connections and correct operation of the repeater. BS port connects to the Donor antenna in order to capture the signal from BTS; MS port connects to the Coverage Antenna so as to spread the signal to the target area. What is more important is that antenna can increase additional gain based on the gain borne by repeater, thus to better reinforce the signal absorption and coverage.
Donor antenna is installed outdoors, usually on rooftop or high end of tower, with big size. Here are two common kinds for recommendation: Parabolic antenna and Directional panel antenna. Parabolic antenna has an embraced round shape and extends a yagi antenna-like antenna from the heart of the net. It can receive signal from 360°and owns strong gain up to 21.5dBi. Directional panel antenna, namely a board-like antenna, is sensitive to seize the signal from certain angle. It targets outdoors with weaker signal but clear direction to BTS. The gain of this antenna can be made to a moderate 15dBi, in avoidance of much amplified noise interference.
Coverage antenna is deployed indoors, usually on the ceiling or against the wall, with small size. There also two common types: Omni ceiling antenna and Directional panel antenna. Omni ceiling antenna is designed similar to a lamp in purpose of harmonizing with the decoration in the ceiling. It is suitable for areas having equal distance from center. But for areas that is long and narrow rectangle, Directional panel antenna will surpass, due to its good directivity.
5. Aware of SPECIAL ENVIRONMENT
Sometimes repeater will be demanded in some harsh environment. For example, intense cold region, where repeater should be assured nonstop power supply and solid case. Once the repeater stops, it will be dead and hard to restart again. And the case should be strong enough to defend against ice, snow, wind corrosion. Another example, the tropical area where is humid and blazing all year round, requires good cooling system and waterproof case, in case of overheating burns out the module and the equipment. High humidity will truce into the case if it is protected poorly, which will shorten the lifespan of inside modules. You may inform of the special environment the repeater will be installed, and the engineer will consider IP65 or higher standard, specific material-made solution for you.
Do you think everything is done after successful installing the repeater? No way. Repeater supervision is equally important for the maintenance staff.
Alarm report is a standard function of all ACTION repeaters. Local access like Web browser GUI local via WiFi hotspot or RJ45 interface connection is available for on-site commission and monitor. Concerning repeater site is often far away from the Office, remote monitor is also optional via 3G/4G wireless modem or IP connectivity. The latest NMS developed by us is the Cloud NMS, which can monitor multiple repeaters’ status at a time, and operate realtime command or change to the equipment simply.
7. Easy to MISS
We offer not only the repeater, but also the accessories to pair with it. Power adapter is one of the elements in customizing repeater. Different country has different standard on the power supply, like 220V, 230V, AC, DC, 9V5A, 9V7A, etc. Suppliers sometimes provide accordingly power adapter based on the customer’s region or the stated project region. Make sure you check all the items listing on the datasheet or specification, and comment in time whenever there is a discrepancy.
Above are simple steps to customize a repeater from a Chinese manufacturer. If you get time, to pay a visit to the factory will be a good idea for further evaluation. As the old saying goes, seeing is believing. Good quality and rich technical experience will convince us naturally.