SMA vs RP-SMA what is the difference ?

When looking for SMA you may find SMA and RP-SMA connectors. What is the difference in these two?

Reverse polarity SMA (RP-SMA or RSMA) is designed to be incompatible with standard SMA connectors to comply with U.S. FCC regulations which seek to prevent consumers from attaching non-standard aerials to wireless devices.

The male RP-SMA connector has the same external housing as a standard male SMA connector except the center male pin is replaced by a receptacle. The female RP-SMA connector has the same housing as a standard female SMA connector however the pin found on a male SMA connector is on the female RP-SMA connector.

Here are some picture examples to help show the difference.

What is IEEE 802.1X?

    Devices attempting to connect to a LAN or WLAN require an authentication mechanism. IEEE 802.1X, an IEEE Standard for Port-Based Network Access Control (PNAC), provides protected authentication for secure network access.

    An 802.1X network is different from home networks in one major way; it has an authentication server called a RADIUS Server. It checks a user’s credentials to see if they are an active member of the organization and, depending on the network policies, grants users varying levels of access to the network. This allows unique credentials or certificates to be used per user, eliminating the reliance on a single network password that can be easily stolen.

How does 802.1X work?

    802.1X is a network authentication protocol that opens ports for network access when an organization authenticates a user’s identity and authorizes them for access to the network. The user’s identity is determined based on their credentials or certificate, which is confirmed by the RADIUS server. The RADIUS server is able to do this by communicating with the organization’s directory, typically over the LDAP or SAML protocol.

Source :

https://www.securew2.com/solutions/802-1x/#:~:text=802.1X%20RADIUS%20accounting%20involves,server%20when%20the%20session%20begins.

Overview of Open Data Protocol (ODP) ...

The Open Data Protocol (OData) is a protocol to request data through a query string.

The Open Data Protocol (OData) is a protocol to access data on the web. It provides a uniform way to query and manipulate data sets through CRUD operations.

Why we need an OData Service?

Advantages

1. OData is based on RESTful architecture, so we can retrieve data based on an URL query string.
   
   
2. OData supports HTTP, Atom Pub as well as JSON format.
   
   
3. It is very lightweight to use. Since it is lightweight, the performance is very good while interacting between client and service.
   
   
4. It supports for any type of data source. Even you can use your own custom class as a data source.
   
   
5. You can create your own custom methods and expose it.
   
   
6. It supports different HTTP methods:
   
   
   1. GET: Gets one or many entries.
   2. POST: Create a new entry.
   3. PUT: Update an existing entry.
   4. DELETE: Remove an entry.

Limitations

1. It is much less secure as it is purely URL based.

What is the Fresnel Zone?

                 In point to point wireless communications, it is important for the line of sight between two wireless systems to be free from any obstruction (terrain, vegetation, buildings, wind farms and a host of other obstructions). As any interference or obstruction in the LOS can result in a loss of signal. 

              While installing a wireless communication system, it is important to keep an elliptical region between the transmit antenna and the receive antenna free from any obstruction for the proper functioning of the system. 

                This 3D elliptical region between the transmit antenna and the receive antenna is called the Fresnel Zone. The size of the ellipse is determined by the frequency of operation and the distance between the two sites.

What is RSSI and its acceptable signal strength?

RSSI stands for Received Signal Strength Indicator. It is an estimated measure of power level that an RF client device is receiving from an access point or router. At larger distances, the signal gets weaker and the wireless data rates get slower, leading to a lower overall data throughput. Signal is measured by the receive signal strength indicator (RSSI), which in most cases indicates how well a particular radio can hear the remote connected client radios. Indoor RSSI Set-Up Best Practices Indoor RSSI Maximums For mixed use networks: -75 dB to -80 dB For session based networks: (Such as video conferencing, Wi-Fi calling, inventory management, etc.) -60 dB to -65 dB Recommended Tx Output Power on APs For mixed use networks: (Such as web browsing, accessing email, etc.) 18 dBm to 20 dBm on the 5 GHz radio 11 dBm to 14 dBm on the 2.4 GHz radio For session based networks: 11 dBm to 15 dBm on the 5 GHz radio 11 dBm on the 2.4 GHz radio Channel Width Relation to RSSI Wider channels normally have lower RSSI values. Therefore, smaller channel widths are recommended in all but some special circumstances; when configuring EnGenius APs. Note: Special circumstances are low AP density deployments, such as a small home network. A wider channel setting should only be considered after the RF deployment has been qualified. (40 MHz - 80 MHz and channel widths) Visualize your project's RSSI through the subscription-free network design tool, ezWiFi Planner. Try it now to measure your project's projected coverage. Source : https://helpcenter.engeniustech.com/hc/en-us/articles/234761008-What-is-RSSI-and-its-acceptable-signal-strength-#:~:text=RSSI%20stands%20for%20Received%20Signal,a%20lower%20overall%20data%20throughput.