Antenna Terminology
Electronics require antennas to convert data into RF signals (and vice versa). They are coupled with radio transmitters and/or receivers to process the information that is carried over cellular bands. Antenna design and functionality has evolved over time:
Internal Antennas: An antenna can be concealed within the casing of a device, as seen with most smart phones. Internal antennas are potentially more prone to interference due to the close grouping of electrical components.
External Antennas: Situating antennas further away from the rest of the circuit board can help alleviate this problem by maximizing a device's natural reach. Instead of sitting inside the device directly next to the modem or transceiver, they screw into place using SMA connectors and protrude from the equipment (think "rabbit ears").
MIMO: Multiple-Input and Multiple-Output (MIMO) technology expands the throughput capacity of a transceiver by leveraging multiple antennas to simultaneously convert RF signals into data (or vice versa), providing faster transfer speeds as a result. Think of it (loosely) as Carrier Aggregation for antennas -- once again combining individual lanes into a single, coordinated superhighway. Networks must leverage MIMO antenna transmission to be technically considered 4G.
Physical Specifications
Accelerated LTE Routers use industry-standard, female SMA connectors to affix antennas to the internal cellular radio. External antennas improve clarity when compared to internal antennas, which are prone to electromagnetic interference. An extension coaxial cable can also enhance the reach of a device; however, that cabling causes attenuation -- or a degradation in signal quality -- due to the distance the signal travels. Significant attenuation typically begins at 30 feet of cabling.
Certain Accelerated products, e.g. the 6300-CX Cellular Extender and 6330-MX LTE Router, are designed to provide the ability to place the cellular router where reception is best (moving the "radio" is always preferred). This allows the device to "capture" optimal Radio Frequency (RF) before converting it to IP packets and transmit data via Ethernet cabling, an approach that yields increased performance and cost savings over coax cabling. Accelerated can also provide a battery pack for site surveys, creative mounting options, and a (passive) Power-over-Ethernet injector to provide an efficient, flexible deployment at the lowest possible cost. Most Accelerated clients will not require third-party antennas unless deploying a more traditional LTE router (without PoE). It is always preferred to mount a PoE router on an external wall via Ethernet and use the shortest coax cable required to run the external antenna to the outside of a building.
CRITICAL NOTE: Please test the signal strength outside of the building to ensure you have cellular coverage in the area prior to any cabling work. (Tip: Use the site survey battery to do this.)