Overview

This document describes Wi-Fi Affinity in detail, its uses, and how to implement Wi-Fi Affinity for its applicable use cases within the FasCard infrastructure.

What Is Wi-Fi?

Wi-Fi -- (often stylized as WiFi, Wifi, or wifi) The commonly known, most widely used and accepted series of computing networks in the global space that spans numerous wireless network protocols and standards.

Given the wide range of available wireless networks across various radio frequencies and divided channels, host devices (e.g. wireless routers and access points) and clients (desktop and mobile devices, or anything that uses Wi-Fi or similar radio frequencies), competition for airspace is very common.

To simplify, the more devices using the same bands of frequencies and channels, the more congested the wireless airspace becomes.

Table of Contents



Introduction

Wi-Fi in the context of the FasCard system is the primary means of communication between host device(s) (Satellite Access Point (SAP), or simply 'satellite') and respective client(s) (FasCard Reader, Touch Kiosk, Add Value Kiosk, or simply 'reader' for the purpose of this document). All FasCard client equipment is preconfigured to search for and communicate with any unique host satellite(s). Satellite and reader communications are linked and, as a result, indiscriminate between identical satellites in the same location.

Symptom

If more than one satellite exists in a location and is within proximity of more than one connected reader, as every satellites' base SSID and connection information is identical, these indiscriminate communications may cause a reader to connect to whichever satellite communicates with it first, even if said satellite was far enough away to provide a weak signal or is already communicating with an excessively high volume of other readers (fig. 1):



Fig. 1 - Satellite-to-reader imbalanced communications, visual example.


This can cause a load imbalance where one satellite holds a much greater reader connection count (fig. 2), which can result in a gradual, noticeable rise in potential delays in communication due to Wi-Fi traffic congestion through both a heightened volume of connected readers on the same device channel(s) and broadcast distance limitations. This is typically evident when one or more satellites may have far less than 50% of the overall reader volume connected vs. its counterpart(s), and/or if an offset reader is connected to the furthest satellite away from its nearest neighbor and the signal strength is exceptionally low.


Fig. 2 - Load Imbalance on FasCard Admin Site, Example.

Solution

Wi-Fi Affinity was recently added to aide in clearing this confusion by allowing satellites and readers to be preferentially assigned, giving priority for a reader to communicate to whichever satellite is chosen. This not only allows for a reader to be assigned to the most convenient satellite distance-wise for communications, it can aide in load balancing through a more even distribution of communication by having control of the volume of (and which) readers that can connect to an individually chosen satellite. A couple of use cases where this can be highly beneficial may include:

  • A laundromat with 2-4 satellites and a volume of readers well over 60 in an open public area.
  • Divided laundry areas where some of the adjacent equipment may still be within range of a satellite in an opposing section or room.
  • A multi-housing complex wherein the laundry rooms are either only a few feet apart or one floor directly above or below and satellites accommodate for each room.

Wi-Fi Affinity, alongside proper positioning of satellites for even broadcast distribution (figs. 3-4) and individually setting each Satellite to a different WiFi Channel, would aide in more efficient, consistent communications.


Fig. 3 - Proper affinity without moving satellites, visual example.


Fig. 4 - Proper affinity with repositioning of satellites, visual example.

The two example images above reflect what may occur based on how Wi-Fi Affinity by itself, or how Wi-Fi Affinity with proper positioning of satellites, could dramatically change the scope of a store's reader communications. The more devices that are assigned closer to its respective satellite, the better the signal quality and responsiveness of a FasCard/FLEX reader.

How It Works

Every satellite has an overall broad SSID (often identified as a series of random letters, numbers, and special characters: " @Zx*L9ph 7k3<v!_ " as it would appear when searching for a Wi-Fi connection) that readers connect to. Wi-Fi Affinity, on the other hand, allows for a reader to be configured on the FasCard Admin Site to selectively choose which satellite it wants to connect to. This is accomplished by assigning a Wi-Fi Affinity to a satellite. When a Wi-Fi Affinity is set for a particular satellite, that satellite is assigned a second unique SSID for the reader to search for and prioritize connecting to first, when a reader is correctly linked to its respective Affinity. Should connecting to its assigned satellite be unsuccessful, the reader will then default to searching for and connecting to the overall broad SSID until the reader can reconnect with its affinity again.


What Is Needed

  • At least two (2) satellites in a single location. Affinity setup is not required when there is only one Satellite at a single location.
    • When affinities are set up with multiple satellites at a single location, each satellite would need to be on a different Wi-Fi channel. 
      • Even if more than one device may have an affinity with separate satellites, competition for the same airspace remains a constant when all devices are broadcasting and receiving information on the same Wi-Fi channel.
  • All related satellites updated to satellite firmware v1.25.02 or above.
  • FasCard readers and kiosks updated to an available Core 9+ reader firmware.


Setup Instructions


Wi-Fi Affinity is only compatible with updated FasCard Satellites on firmware version 1.25.02+ and FasCard Readers updated to a Core 9+ firmware.

Setting WiFi Affinity - Satellites

  1. Log in to the FasCard Admin site. If you have multiple accounts, select the account that has the site listed where you would want satellite affinity assigned.


  2. Click the Setup tab, followed by the Locations sub-tab. Select a location or add a new location as described in Location Setup.

  3. In the Satellites section, click on the first satellite you want to assign a WiFi Affinity to.
    1. If no satellites exist (e.g. new store setups), make sure to Add Satellites, first.


  4. Click on the WiFi Affinity dropdown and set an Affinity number for the satellite in question.


    1. When setting a WiFi Affinity, it is strongly recommended to also change the WiFi Channel to a different channel than the other satellite(s).
  5. Repeat the process for any remaining satellites you want to assign a WiFi Affinity.


Setting WiFi Affinity - Machines

  1. Click the Machines sub-tab.
    1. If multiple locations are configured for the FasCard account, select the appropriate location. If only one location is configured, it will be selected automatically.

  2. Select the first machine you would want to assign a WiFi Affinity to.
    1. If no machines exist, add new machines as described in FasCard Admin Site - Machine Setup.

  3. Click on the WiFi Affinity dropdown and select the WiFi Affinity you would want to set the machine's affinity to.


  4. Repeat the process for any remaining machines you want to assign a WiFi Affinity to (preferably to a Satellite within comparable range of said nearby readers).


Location Status Verification

Once you have WiFi Affinities assigned, you will be able to see which readers are indexed to which satellites using the System tab > System Maintenance sub-tab.


Tips

  • Since every reader can be given an affinity, there is no hard limit to how many readers can have affinities split to the various satellites in a single location. However, the Satellite limit is four (4).
  • When a reader has an assigned Wi-Fi Affinity and is unable to connect to its assigned satellite, the periodic retry attempts would be as follows:
    • After the first time it can't find the preferred satellite first, it will retry after only 5 minutes (hoping that the satellite was merely rebooted and is now available once again).
    • After the second failed connection to the preferred satellite, it will retry after another 15 minutes.
    • For retries #3-5, it will retry once per hour.
    • For retries #6-10, it will retry once every 6 hours.
    • After that it will retry once per day.
  • A successful connection to the preferred satellite resets the periodic retry attempts counter, so that the next failure after that would be again retried after only 5 minutes.


Additional Notes

  • While modern Wi-Fi stream advancements such as MU-MIMO (multiple user, multiple input, multiple output) help alleviate this by having multiple individual streams for bandwidth distribution as opposed to a single stream, such is still only limited to compatible host and client devices as well as the number of multiple streams available. The FasCard system does not support MU-MIMO capabilities.