When choosing a new wireless doorphone system for the ever-expanding portfolio of home or business wireless devices, you should first consider compatibility with existing (or neighbors) products. You should also take into account the range and services you need.
Wireless Intercom Frequencies
There are several frequency ranges in the United States for wireless products for licensed consumers. These are 49MHz, 900MHz, 2.4GHz, 5.8GHz and Family Radio Service (FRS) bands. Recently, FCC has added the Multi-Use Radio (MURS) service. Radio frequencies are similar in Canada, but MURS can not be used there.
Back when consumer wireless products were first introduced, these wireless products used a 49 MHz frequency spectrum. Early wireless phones use this spectrum and are still used by cheap baby monitors and other low-end wireless units. Short-range and many interferences. It is unlikely you will find wireless intercom systems that are more likely to use this spectrum, or if you do not, you will not.
Later on, 900MHz products using analogue technology were marketed. Either 49MHz or early 900MHz products provide any security. Anyone with the same frequency device can listen to the conversations. The latest digital spread spectrum 900 MHz products share digital transmission within a frequency range so other devices can not hear conversations. Digital spread spectrum intercoms are also larger than analogue 900Mhz units. There are currently at least two wireless door phones in the market, but only one of them uses a digital spread spectrum. The spread spectrum wireless entryphone system can communicate up to 1000 feet in distance.
2.4GHz devices were on the market. Within this range, there are more and more cordless phones and other devices. As far as doorphone systems are concerned, video telephony systems are the primary users of this domain, although the only wireless video intercom on the market has recently ceased. The 2.4 GHz frequency range is the frequency range used by the wireless WiFi data networks (802.11B / G) in homes and businesses, so that products in this range can interfere with each other.
Family Radio Service (462-467 MHz) is in the Ultra High Frequency (UHF) band and essentially improves old walkie talkies. These handheld radios are widely sold and widely used, so any intercom systems in this range must compete with these handheld radios (and anyone can listen to their conversations). There are no known wireless intercom systems that use FRS.
Now the 5.8GHz products are starting to appear in the wireless phone arena. There are no compatibility issues between 5.8 GHz and 2.4 GHz devices, so there is no problem with mixing. However, there are currently no known wireless intercom systems in this range.
There are some intercom systems that claim to be wireless but actually use home or corporate power networks to send and receive transmissions from the intercom. These are often referred to as "FM wireless intercoms", even though they often transmit your home wires in the AM band. Only connect a power adapter to the wall using them. These systems are very prone to humming and humming, and are not recommended unless they are willing to take advantage of this option. Because the house wire is 240 volts and is divided into 120 languages, it also has problems with the blocking sign. Part of the house or business can work well where the other party does not. These door phones are usually the cheapest intercoms for the knot.
Long Range Wireless Intercoms
The latest addition to the wireless intercom market is the products in the MURS frequency range. MURS is a service in the VHF (very high frequency) 150 MHz radio spectrum. MURS is four times the FRS radio performance. Unlike the FRS, you can add a larger or an external antenna to increase range. If you want to place an antenna on top of the house, you can do it with MURS. Some antennas claim that an external antenna can increase the transmitter's actual radiation power by 4 times. These MURS intercoms are capable of transmitting up to four miles and perhaps even an external antenna.
The Federal Communications Commission (FCC) in the United States does not require permission to use MURS frequencies so you do not have to go through this process.
There are 5 MURS channels and 38 interference eliminators or "silent codes" that can be used on each channel. These silent codes keep the radio silent without another radio being programmed on the same channel and silent code. You may not have to worry about these codes because MURS is extremely easy to use. MURS radios have only a few manufacturers, so in most of these areas it is difficult to find the traffic frequency.
The MURS Intercom system is the wireless door phone you need when you talk about great property or buildings. MURS can be communicated not only at home but also in neighboring homes. You can even add one handheld to the MURS intercom system so your home can be kept away.
Long Term Wireless Outdoor Speakers
The commercially available Wireless Call Boxes are also available for communicating with two-way radios and base stations. These cordless telephones are waterproof and are designed for outdoor use. Doors or doors can be opened remotely if there is a model with a gate relay. Calling boxes also have vandal-resistant housing with stainless steel front panels. They range up to one mile or more when using an external antenna. These wireless calling boxes can be operated with batteries, operated with AC-DC converter or solar power. Caller boxes are available at UHF and VHF frequencies, so they can match the existing two-way radios. You can receive call barrels that are not allowed on MURS frequencies, so they can be used with MURS intercoms or radios.
The advantage of the wireless enclosure is that it saves you money by not having to wire a wire and deliver expensive cable to the unit. You do not even have to pay these wireless systems for air or telephone charges. Another advantage is that since the unit is wireless, units capable of monitoring units can carry handheld radios that communicate with the calling cabinet. This allows you to monitor people.
Wireless Door Phone Features
Another thing to consider is what features need to be for that application. Commercial applications often require a wide range of services. For example, the MURS wireless system has many products that can be used with it. Not only can you get military-grade bi-directional radios that have many headphones options, but you can receive base stations, wireless calling boxes, solar optic options, wireless public addressing systems, customer service calls, wireless remote switches, and motion detection devices. For less commercial or residential use, the 900MHz doorphone system has an outdoor doorphone and an intercom door phone that can be used with the indoor doorphone.
So the chosen wireless doorphone system depends on the app, the wireless devices, range, and budget that are already in your home or business. But after choosing the right system, you will enjoy the comfort of the wireless intercom system over the next few years.
Source by sbobet