Multiple Access Point Architectures and Wi-Fi Whole Home Coverage
As mentioned in a previous blog post on AP Coordination by my colleague Neeharika Allanki, homes sizes are growing and the number of client devices in a home network are increasing exponentially. There is a need for not only consistent performance in terms of throughput and connectivity, but also Wi-Fi coverage throughout the home. Consumers often need more than one Wi-Fi Access Point (AP) in the home network to provide that coverage.
Many houses in the world do not have existing wires that can be used to network these APs together, and so one of the easiest and most cost effective ways to provide whole home Wi-Fi coverage is by using Wi-Fi itself to connect together the APs in the home. The technologies available today that can do this are Mesh APs (MAPs), Repeaters or Extenders.
Wireless repeaters and extenders have been around for years due to consumers seeing the need to expand Wi-Fi coverage in their homes. While some form of wireless mesh networking has been around for more than ten years, until recently there were not products designed for the home that used mesh to connect multiple APs. In the past year, there has been a dizzying array of product announcements and introductions for home Wi-Fi coverage, with many of them using mesh networking.
Mesh Access points (MAPs) are quickly gaining traction in home networks mainly due to ease of installation (even over Repeaters/Extenders) and the promise of high throughput with whole home coverage. A mesh AP network can be defined as a self-healing, self-forming, and self-optimizing network of MAPs. Each MAP can communicate with others using smart routing protocols and thereby choose an optimal path in order to relay the data from one point to another.
As mentioned before in our AP Coordination blog, client steering (moving Wi-Fi clients to the best AP in each location) and band steering (moving and keeping Wi-Fi clients on the best band: 2.4 GHz or 5 GHz) are very important in any multi-AP solution, such as mesh or an AP + repeaters/extenders network. This is needed to ensure that each mobile client stays connected to the best AP for its current location. Without client steering, Wi-Fi clients may show connectivity to Wi-Fi, but throughput may suffer tremendously. This often shows up as the dreaded “Buffering…” message when streaming a video or a slow progress bar when loading a web page. In a fully wireless multiple AP solution, client steering and band steering is even more critical due to the throughput and latency penalty when traffic is repeated over Wi-Fi from one AP to another. As MAPs communicate with each other to form the mesh network, they implement some form of AP Coordination, and it is usually proprietary in nature.
CableLabs recently tested mesh networking solutions and AP + repeater solutions consisting of 3 APs in a 5000+ sq. ft. test house. We performed throughput, jitter, latency and coverage testing at more than twenty locations in and around the house. We found that we were able to run two streaming videos, at HD bitrates (~20Mbps), to video clients in the home while also delivering over 50Mbps to our test client. Both mesh and AP + repeater solutions were able to handle this video throughput, as well as deliver over 50Mbps throughput throughout the house and even to some areas 20’ outside the house. This is excellent news for consumers whose access to the Internet is wireless and who want that access everywhere in their homes.
CableLabs is working with vendors to define a standardized AP Coordination Protocol that would allow all APs in a home network to share information to allow them to make client steering decisions, along with other network maintenance tasks.