Cambium PMP 450 AP, User Manual

Page: 57 / 301

Chapter 1: Product description Wireless operation
Page 1-19
Encryption
The 450 Platform Family supports optional encryption for data transmitted over the wireless link. The 450
Platform Family supports the following forms of encryption for security of the wireless link:

DES (Data Encryption Standard) : An over-the-air link encryption option that uses secret 56-bit keys
and 8 parity bits. DES performs a series of bit permutations, substitutions, and recombination
operations on blocks of data. DES encryption does not affect the performance or throughput of the
system.

AES (Advanced Encryption Standard): An over-the-air link encryption option that uses the Rijndael
algorithm and 128-bit keys and 256-bit key size to establish a higher level of security than DES. AES
products are certified as compliant with the Federal Information Processing Standards (FIPS 197) in
the U.S.A.
The default setting on an AP is "Disabled".
MIMO
Multiple-Input Multiple-Output (MIMO) techniques provide protection against fading and increase the
probability that the receiver decodes a usable signal. When the effects of MIMO are combined with those
of OFDM techniques and a high link budget, there is a high probability of a robust connection over a non-
line-of-sight path.
The sub-features that comprises the MIMO techniques utilized in the 450 Platform Family ODUs are:

MIMO-A: This technique enables 450 Platform Family radio to use a scheme that optimizes coverage
by transmitting the same data over both antennas. This redundancy improves the signal to noise ratio
at the receiver making it more robust.

MIMO-B: This technique provides the ability to double the throughput of a radio transmission under
proper RF conditions. Different data streams are transmitted simultaneously on two different
antennas.
MU-MIMO
Multiple-input multiple-output, or MIMO, is a range of technologies used to multiply the capacity of a
wireless connection without requiring more spectrum.
Although traditional MIMO techniques are focused on increasing the bandwidth available between two
wireless nodes, multi-user MIMO (MU-MIMO) applies these technologies to increase overall wireless
network capacity by allowing an access point to communicate wirelessly with more than one wireless
node at once.
A MU-MIMO access point features an array of antennas. When the AP decides to communicate with
multiple nodes at the same time, it creates multiple simultaneous beams each directed to a specific node.
This is contrast to a traditional wireless system, where two wireless nodes cannot communicate on the
same channel to the same access point at the same time, without causing significant self-interference
and degrading the overall wireless network performance.