Use case 1 – Capacity Centric, AP serving 11ax and legacy clients
In this scenario, the network is serving 4 Wi-Fi 6 (11ax) clients, each of these is a 2x2 client (a common configuration for mobile 11ax clients) along with 2 legacy clients (marked in the image above with “L”), the clients are spread across the home and are operating concurrently in downlink (AP transmitting to clients).
Rigid MIMO System: Would aim to utilize both interfaces and load balance to best practice – steering the legacy clients to 2.4GHz (as it is a narrower bandwidth) and servings the four 11ax STA with DL MU-MIMO over 5GHz (80MHz channel).
ElasticMIMO System: The optimization algorithm allocated 6 antennas to the 5GHz and 2 antennas to the 2.4GHz, while serving the legacy clients on the 2.4GHz and the four 11ax clients on 5GHz with DL MU-MIMO (80MHz channel).
Compared results – four 11ax clients (2x2) & two legacy clients (downlink)
As can be seen, by allocating dynamically 6 antennas to the 5GHz, the capacity of the interface almost doubles with minimal impact on the 2.4GHz legacy client performance.
Running the simulation for the same clients in the uplink direction yields very similar benefits as illustrated in the following result chart:
Compared results – four 11ax clients (2x2) & two legacy clients (uplink)
Use case 2 – Coverage Centric, AP serving Homespot / Hotspot
In this scenario the network is serving 2 Wi-Fi 6 (11ax) set-top-boxes that are active in the home, each consuming dual UHD streams (~100Mbps each STB), while serving additional clients roaming on the street. Roaming clients are spread over a distance, at a pathloss of up to 110-115dB from the AP.
Rigid MIMO System: Would aim to utilize both interfaces and load balance to best practice – serving the 11ax STB on 5GHz, serving the roaming clients on the street on 2.4GHz (4x4). Some of the clients are failing to establish a link.
ElasticMIMO System: The optimization algorithm allocated 6 antennas to the 2.4GHz and 2 antennas to the 5GHz, having enough capacity to easily drive 100Mbps to each of the STBs, while serving the roaming clients much better on the 2.4GHz (6x6).
The performance to the two 802.11ax video devices that require 8K or dual 4K UHD streams (total of 100Mbps per device) at the 5GHz band is the same for both systems. However, with 6 antennas allocated to the 2.4GHz band, the performance of the devices connecting from a remote location is dramatically improved – no devices are out of service and the total performance of those devices is greatly improved.
The additional link budget of the 6 antenna system would also contribute to a much more resilient link, improving the fading-mitigation of the devices connecting from a far location.
Nonetheless, the simulation does not represent this important benefit as the performance of the 4x4 system would likely be reduced due to the high PER caused by the fading.
Use case 3 – Multi Services – STB & Mix of Mobile Clients
In this scenario, the network is serving a mix of dedicated video clients and a multitude of data clients spread across the home. The network is serving four concurrent Wi-Fi 6 (11ax) set-top-boxes, each of 4x4 configuration, consuming all together ~ 250Mbps of video service, along with 2x2 Wi-Fi 6 clients that are concurrently active.
Video service to Set-Top-Box is of higher priority and should be addressed first before serving the data clients. Furthermore, considering the distribution of the STB across the home and the traffic pattern nature of video, the assumption is that either SU-MIMO or SU-OFDMA, and not MU-MIMO, would be used with the STB.
Rigid MIMO: Serving the STB (SU/OFDMA) + 11ax clients (MU) on 5GHz 4x4, and the legacy clients over 2.4GHz.
ElasticMIMO: Algorithm allocated 6 chains to 5GHz serving the STB (SU / OFDMA) + 11ax clients (MU) and 2 chains to 2.4GHz for Legacy clients.
The following chart indicates the amount of airtime % required to serve the four 4x4 set-top-boxes with 250Mbps. The x-axis values represent the set-top-boxes’ average path-loss attenuation (in dB) and the y-axis values represent the required airtime %. Any value higher than 100% indicates that there is not enough airtime to serve the 250Mbps to the 4 STB:
Utilizing the remaining airtime to serve the 11ax data clients yields the following result:
Analyzing achievable performance of both systems yields the following observations:
Serving 4 concurrent UHD along with 1Gbps of wireless service –
- A rigid MIMO system fails to achieve the use-case even at short range (50dB path loss, which is in the same room as the AP)
- An ElasticMIMO system can meet the use-case up to ~78dB path loss (which is similar to the expected attenuation between two adjacent rooms)
Serving 4 concurrent UHD along with 500Mbps of wireless service –
- A rigid MIMO system can meet the use-case up to ~77dB path loss
- An ElasticMIMO system can meet the use-case up to 90dB path loss
Use case 4 – Multi AP, Backhaul Considerations
For multi-AP wireless fabric, we have analyzed wireless link performance, whereas for a rigid MIMO system it is a fixed 4x4 to a 4x4 link. For ElasticMIMO system both the root-AP and the extender have their radio elastic.
Links are assumed possible at either 5GHz or 2.4GHz, while at 5GHz operation is assumed using 80MHz channel bandwidth, while using 40MHz in 2.4GHz.
Rigid MIMO: Backhaul link limited to 4x4-to-4x4 with 4SS at either 5GHz or 2.4GHz
Elastic MIMO: Backhaul link may reach up to 6x6-to-6x6 with 6SS at either 5GHz or 2.4GHz
On 5GHz with 80MHz Channel BW
On 2.4GHz with 40MHz Channel BW
For 1Gbps of whole home service:
- RigidMIMO: A 4x4-to-4x4 link can deliver 1Gbps of throughput up to 66dB of path-loss, which is similar to the signal attenuation through a single wall (i.e. the next room). Typically it is not expected that an extender will be placed in such proximity (it will more likely be placed two walls away, or a floor up/down, with path-loss of above 80dB).
- ElasticMIMO: Allows both nodes to use 6x6 antennas in either band and can carry the 1Gbps of service over 80MHz channel to the desired location as it can reach this performance up to 84dB path-loss.
For 500Mbps of whole-home service:
- RigidMIMO: A 4x4-to-4x4 link would require 78% of airtime at 80MHz channel bandwidth to carry 500Mbps to the desired extender location (83dB path loss). Thus, under repeater mode it does not have sufficient airtime remaining to serve extended clients (only 22% of airtime remained for service). At 2.4GHz with 40MHz a 4x4 link can’t carry 500Mbps at 83dB path loss.
Furthermore, if the 4x4-to-4x4 link is dedicated for backhaul (e.g. as in tri-band configuration) there is not enough airtime to serve two extenders concurrently both with 500Mbps.
- ElasticMIMO: Up to 6x6-to-6x6 for the backhaul link at either band. In 5GHz only 47% of airtime is required to carry the 500Mbps to the target extender location, having enough time to accomplish both extender scenario– having enough airtime to serve also front-haul connected clients with 53% of airtime remaining (this would be the scenario of dual band devices); or be able to backhaul in full 500Mbps to two extenders (e.g. in a tri-band scenario when the link is used only to interconnect between the nodes).
At 2.4GHz ElasticMIMO can carry 500Mbps up to 85dB of path loss, making 2.4GHz a viable backhaul option (not possible for 4x4).