Article: What is EnJet?


EnGenius have recently launched Version 2 models of a number of their outdoor AP which now include a new technology called EnJet.

What Exactly Is EnJet?
In a traditional wireless bridge setup, Wi-Fi will utilise a protocol called CSMA/CA (Carrier-Sense Multiple Access With Collision Avoidance) that aims to avoid collision before transmitting data. This means that each unit will first detect any potential collisions that could interrupt transmission, but this has the consequence of increasing latency. This problem is exasperated as the size of the network and distance of communication increases.

Therefore to resolve this problem EnGenius developed EnJet, a technology that uses PtP (Precision Time Protocol) and PtMP (Point-to-Multipoint Communication) to allow a network to overcome the latency of the CSMA/CA protocol. This is achieved by assigning Access Points / Bridging Units a predefined time slot in which they can communicate on a schedule with other units on the same network.  

Please note that for obvious reasons EnJet units are not backwards compatible with non-EnJet units.

What Does EnJet Mean For The Future Of Communication?
Imagine you have five units that are individually sending data to a single recipient, for example five ENS500-AC all transmitting to a single ENS500EXT-AC. Under the existing CSMA/CA protocol, all the data will be sent at the same time and it will be pot luck on whose data is received first.

In reality this is done in milliseconds, so a human would not normally notice unless they were using a service such as VoIP. In other words, each unit will keep sending its data until it eventually gets through, which will cause latency on the network.
EnJet resolves this problem by organising wireless communication on a schedule. A good analogy is to imagine the hands and face of a clock in which each hour represents the period in which each unit will have permission to send data. Unit one will send data at 12pm, unit two will send at 1pm, and so on. EnJet will also ensure that the data sent from these units will always reach the destination without the risk of packet loss and the chance that another unit’s traffic will interrupt.

How Does EnJet Optimise Data Traffic?
As mentioned previously, VoIP is a service that requires no latency to function correctly, especially over a wireless bridge, therefore EnJet will prioritise VoIP traffic by giving it a higher priority over HTML (Web Browsing) traffic. This makes sense because VoIP and Real-Time Voice Transmissions are more latency intensive in comparison to watching a video on YouTube.

In conclusion EnJet is a technology developed by EnGenius in order to resolve the shortcomings of CSMA/CA by increasing network efficiency when transmitting over a wireless bridge and ensuring that all data passed across the bridge is received in full and that no data packets are dropped.