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Wireless Knowledge Center > Application Notes & Drawings |
Select Engineering Drawings |
Generic application drawings for frequently encountered scenarios. Contact us for more information or for an application not shown here.
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| Application |
Remarks |
| Cellular or WiMax Signal Strength Improvement for Buildings |
Covers instances where the in-building received signal strength is too weak. If outdoor signal is strong enough involves merely using low loss cables and high gain antenna to bypass walls and bring in the signal (including lightning protection). Sometimes RF bidirectional amplifiers or repeaters are needed. Gain dependent on available link budget. |
| Cellular or WiMax Signal Strength Improvement for Mobile Units (vehicles, RV's, boats) |
| This includes two distinct classes of applications: |
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Mobile applications: amplifiers, antennas, modems & radios need special design features to work in a moving vehicle. |
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Nomadic applications including temporary sites like construction trailers. These need design contraints similar to in-building solutions. |
| Also some applications may require special vibration, shock & temperature spec's. |
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| Medium Range Wireless |
Typically less than 1mile and <54 mbps systems. Most common application involves extending the range of your 802.11g/n WiFi network or accessing a distant WLAN. Several design tradeoffs exist depending on coverage radius desired, co-channel & adjacent-channel interferers, # of concurrent users, network topology & density (especially high AP density with hidden nodes). We apply high gain antenna with varying directivity, bi-directional amplifiers, frequency converters, power-line adapters, wireless repeaters, high power AP's & client adapters etc. |
| Long Range Wireless |
Typically greater than 1 mile to several miles. For greatest range and datarate licensed frequency bands exist (including lightly licensed bands such as 3.65 GHz for WiMax and 71-76 GHz & 81-86 GHz E-Band). These links are non-trivial and several RF/Wireless Engineering design constraints need consideration. |
| Wireless Video Surveillance |
At Rfwel we focus exclusively on the wireless video backhaul including accessories such as remote/ backup power required to enable such an application. Special considerations such as sustained throughput and latency/ jitter critical for real-time wireless video. |
| Wireless Automation & Control |
Includes Wireless thermostats, wireless temperature & humidity sensors and remote control of HVAC systems. |
| Radio Over IP & Interoperability |
Our expertise is on the enabling traditional radio circuits over Wireless IP networks. |
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Cellular Amplifiers, High Gain Antennas & Cellular 3G Routers |
| NOTES: |
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Lighting surge suppression devices critical if mounting antenna in roof. Appropriate lightning device properly grounded in accordance with NEC or other applicable local regulations STRONGLY recommended more on lightning devices |
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Careful installation required to prevent oscillations caused by co-channel interference between outdoor antenna and indoor antenna. Observer minimum separation distances. Too much gain just as bad as too little. If gain too strong consider using attenuators to lower the gain. |
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Amplifier re-radiates boosted signal up to a maximum area. Consider carefully distance between cellular device and internal dome antenna. |
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Carefully consider total link budget (i.e how much signal strength you need vs how much is lost in cables/connectors) from outside antenna to mobile device. |
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Need information on what frequency band your carrier is operating on in your geographic area if getting single band amplifiers. |
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Not all amplifiers or cellular routers are created equal!!! |
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Direct Connect In-Building Omnidirectional Dual-Band WWAN
Direct Connect In-Building Directional Yagi WWAN
Direct Connect In-Building Directional Yagi WWAN (for Option Globesurfer III FWT)
Wireless In-Building Omnidirectional Dual-Band WWAN
Wireless In-Building Directional Yagi WWAN
High Gain Directional Antenna for WiMax Modem (for Xohm/Clearwire Zyxel Modem)
High Gain Directional Antenna for WiMax Modem (with lightning discharge device)
Yagi Antenna for Option Globesurfer III (generic for any radio - just change antenna adapter)
1900MHz In-Building Solution for Extremely Low RSS & Wide Area Coverage (Sprint PCS)
To improve indoor coverage of dual 3G/4G systems. We use a high-gain directional cellular band antenna (1.9GHz PCS) and a high-gain directional WiMax antenna (2.6GHz). We pass the cellular signal through an RF bidirectional amplifier (BDA) and combine it with the WiMax signal using a low-loss 2-way diplexer. We then couple the signal to the 3G/4G modem. Contact us if interested in using MIMO diversity as well or see the forums.
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Mobile Cellular Amplifiers. Mobile 3G/ 4G Routers & Antennas |
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Need an amplifier that is capable of handling mobility (doppler spread). |
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Need an omnidirectional antenna since direction of maximum received signal strength varies depending on where vehicle is more on cellular antennas |
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Typically powered by a DC/DC converter from the car battery. |
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Direct-Connect Dualband Vehicle WWAN
Direct-Connect Dualband Vehicle WWAN (for Option Globesufer III FWT)
RV/ Camper Cellular Amplifier & 3G/ 4G Router
Mobile Office Communication w/ MultiWAN Router (combines 3G cards, WiFi, Sat & WiMax)
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Medium Range Wireless Bridging Solutions |
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These applications pertain to situations where you need to extend your WLAN or Internet access outside the range of 802.11b/g/n radios i.e greater than ~500ft (150m) to about 3500ft (~1km) and at high datarate ~10mbps or more. See below for long range links > 1mile.
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| NOTES: |
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802.11n radios on the right channel will easily give you in excess of 300FT of coverage. Before spending money on costly bridges investigate whether you could boost the performance of your existing system (you often can using directional antennas, amplifiers, power-line adapters etc.) Learn More |
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Lighting surge suppression devices critical if mounting antenna in roof. Appropriate lightning device properly grounded in accordance with NEC or other applicable local regulations STRONGLY recommended more on lightning devices |
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Do be a good neighbor and observe FCC EIRP (Effective Isotropic Radiated Power). Where possible utilize high directivity antennas to reduce chances of interfering with other neighboring unlicensed band devices. |
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PTP Bridge & WDS (Point-to-Point Bridge & Wireless Distribution System mode)
Amplifying WiFi & Long Range WiFi USB Adapter
Converting Cellular to WiFi then Bridging Distant Site
Medium Range Point-to-Point Link w/ WiMax Backhaul (~1Km 5.8GHz, Clear WiMax)
To extend a WLAN (WiFi) or LAN network to a remote location up to 3000ft away or to get Internet to a remote location. One location has DSL/Cable modem but remote location doesn't. Long ranges above 500ft require a line of sight for best performance. To avoid 2.4GHz interference consider using 5.8GHz radios for the Point-to-Point (PTP) link. Minimize coaxial cable runs to high gain antennas.
Large Coverage WiFi Setup (use high power AP, high gain antennas & 2.4 Ghz Amplifiers)
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Long Range Wireless Bridging Solutions |
| By long range we mean > 1mile to several miles. Depending on desired data-rate, available frequency band and available line-of-sight, 50+ miles possible with tens of mbps and decent fade margin. Setting up a long-range wireless link is not a trivial exercise especially if using an unlicensed frequency band and trying to push throughput. |
| NOTES: |
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RF line-of-sight (LOS) is not the same as optical line-of-sight. You could have an optical line-of-sight and still not have RF LOS if there are obstructions in the Fresnel Zone (and Fresnel zone depends on wavelenght/frequency of signal). Non-line-of-sight (NLOS) and near-line-of-sight (nLOS) links possible but at reduced datarate Learn More |
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Typically the higher the frequency band the more the available bandwidth hence the higher the possible datarate (simplest form is bound by shannon channel capacity proportional to the Bandwidth and log of SNR). So millimeter wave (MMW) at 60GHz allows for better datarate than 5.8GHz or 900MHz but since the beamwidth is much smaller it requires more careful alignment and since wavelength is much lower more susceptible to rain fade. |
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Often the Capex required to implement long-range links is outweighed by 3G/ 4G WWAN links even after considering monthly subscription costs. The latter further provides for almost seamless migration to newer faster protocols. Contact us to learn more. |
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{{ contact us for specific application examples }} |
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Wireless Video Surveillance Applications |
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Be realistic with your expectations. It would be magic to video stream high quality video/audio in real-time on a high latency 1xRTT or EDGE network! Learn More |
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All new projects should utilize IP cameras. Where possible legacy analog cameras should be replaced or encoded to IP. |
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With wireless video surveillance it takes more than just high speed backhaul. Jitter and latency can kill the project. |
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Remote Video Surveillance (Point-to-Multipoint Non-Line-of-Sightn Wireless Backhaul)
Remote Video & Remote Power (PTZ Camer, Solar/PV, Battery Bacup, Long Range PTP) |
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Wireless Telemetry, Automation & Control |
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Most popular wireless thermostat, the Totaline/ Venstar system is too simple to install to deserve any technical drawings. Refer to product page for technical specs More |
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For most residential/ commercial wireless HVAC needs the Totaline/ Vestar or Honeywell RedLINK™ products typicall suffice Learn More |
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As with most other data systems, when trying to remotely monitor environmental conditions such as temperature, humidity, CO2, CO for data logging or as part of a SCADA system, the goal is usually to convert it to IP as early as possible (prefereably at the sensor node) and use TCP/IP transport to remote storage server or monitoring stations. Rfwel's expertise in wireless data transport allows the economical bridging of distant sensors More on DAQ's |
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Wireless Thermostat w/ Telephone Control (for use in 2-wire system)
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Radio Over IP [Over Wireless] & Radio Interoperability |
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ACU-100M Interoperability System allows cross connection of different communciation systems: HF, VHF, UHF, Trunked Systems, Cellular PTT, Cellular Voice, PSTN, Sattelite Systems Learn More |
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The NXU-2A Network Extension Unit allows distribution of Radio Cicuits over IP LAN/WAN Learn More |
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Rfwel then uses our expertise on Wireless distribution systems both local/campus and long range to interconnect different radio transceivers Learn More |
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Radio Over IP Basic System
Eliminating Leased Lines w/ NXU-2A (app note courtesy of Raytheon/JPS)
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