Amazon extends its reach into your neighborhood with Sidewalk

Could Amazon’s new low-bandwidth, long-distance wireless protocol be bigger than Wi-Fi and Bluetooth? Time to take a look under the hood of Amazon Sidewalk and explore what it means for IoT in your neighborhood.
Teresa Mastrangelo
Family on a walk

Network sharing just took on new meaning with the introduction of Amazon Sidewalk, a shared, crowdsourced, neighborhood network that extends connectivity beyond the range of home Wi-Fi to support low-bandwidth, low-power, smart lights, sensors and other devices installed by customers at the edge of their home networks.

By leveraging Bluetooth Low Energy and the 900MHz spectrum, Amazon has developed a new protocol that promises longer range (by more than one kilometer) than Wi-Fi and Bluetooth with lower power usage and complexity than 5G. This extended range will allow customers to place smart devices anywhere on their property, even in places that traditionally were unable to be reached by Wi-Fi or Bluetooth, such as your mailbox or sprinkler system.

Sidewalk, originally announced in September 2019, is expected to launch before the end of 2020. There is no charge to use the service, participation is 100% voluntary and no upgrades are needed for Sidewalk-compatible devices.

How does it work?

The Sidewalk network consists of a Sidewalk network server, Sidewalk gateways, and Sidewalk endpoints.

The Sidewalk gateways (also known as bridges) forward packets to/from the Sidewalk endpoints and the Sidewalk network server. Products that support gateway functionality are Amazon devices, such as Echo devices, Ring Floodlight Cams and Ring Spotlight Cams, that use 900MHz (LoRa and/or frequency-shift keying, and/or Bluetooth Low Energy to provide connection to the Sidewalk network.

Sidewalk endpoints can roam on the Sidewalk network by connecting to Sidewalk gateways. Endpoints are low-bandwidth/low-power smart products such as leak sensors, door locks, lights, or devices you can attach to valuables, keys or pets for location purposes. Sidewalk endpoints can be built and maintained by Amazon or third-party developers, with Tile being the first third-party device authorized to work on Sidewalk.

The Sidewalk network server is the backbone of the Sidewalk network and has the responsibility for verifying that the incoming packets are coming from authorized Sidewalk devices; for routing packets to the desired destination (an application server, endpoint or gateway device), and keeping the network time-synchronized. The Sidewalk network server is operated by Amazon.

Customers with a Sidewalk gateway can voluntarily contribute a small portion of their internet bandwidth to the shared pool to create this shared network that benefits all of the Sidewalk-enabled services within a neighborhood. It should be noted that the shared network will not support high-bandwidth connections like Wi-Fi or cellular – so consumers should not plan on pirating the shared network for other applications.

In order to make sure that there is no degradation to a participant’s home network, Amazon has set the following parameters: the maximum bandwidth of a Sidewalk gateway to the Sidewalk server is 80Kbit/s, while the total monthly data used by Sidewalk enabled-devices, per customer, is capped at 500MBit – the equivalent to streaming about 10 minutes of high-definition video.

Privacy and security top concerns

Since Sidewalk is a shared network; privacy and security are top concerns for customers that choose to participate. As such, Amazon has provided extensive information on how this will be handled.
First and foremost, Amazon Sidewalk has stated that it will limit the type and amount of metadata necessary from Sidewalk endpoints to manage the network. In other words, Sidewalk only uses the metadata to route packets to/from the Sidewalk gateway and then to/from the Application server. In addition, the Sidewalk network server does not know the contents of the packets or the commands sent over Sidewalk.

To ensure privacy, the owners of the endpoints can only view information that pertains to the normal operation of their own device and the gateway owners cannot see what endpoints are receiving support from their gateway (including type of endpoint, when it is connected, how long it is connected or who is the owner of the endpoint).

Information transferred over the Sidewalk network will have three layers of encryption to ensure data is visible only to the intended party. Gateway customers are not able to see that Sidewalk endpoints are connected to their gateway, nor will customers who own endpoints connected to Sidewalk know which gateway they are connected to.

Amazon’s approach to encryption means that Amazon will not be able to interpret the contents of commands or messages sent through Sidewalk by third-party services or endpoints (applications).

  • Layer 1. The Sidewalk application layer enables secure and private communication between the endpoint and the application server.
  • Layer 2. The Sidewalk network layer protects the endpoint’s Sidewalk packet over the air. Plain-text data in this layer is accessible only to the endpoint and the Sidewalk network server.
  • Layer 3. The flex layer, which is added by the Sidewalk gateway, provides the network server with a trusted reference of message-received time and adds an additional layer of packet confidentiality. Plain-text data in this layer is accessible only to the gateway and the Sidewalk network server.

From a security perspective, Amazon Sidewalk is designed to authenticate the identity of all network participants, and to provide authenticity and confidentiality for all packets traversing the network.

Join the collective – Resistance may be futile

Of course, the success of Sidewalk is based on the number of customers that chose to participate. And since participation is completely voluntary, participants have the ability to turn their participation on and off at any time, making network connectivity inconsistent.

Even though the amount of bandwidth contributed by each participant is low – whether or not everyone is interested in sharing is another thing – especially if they personally will not benefit from the network. Furthermore, despite the multiple assurances that your privacy and security is intact, we’ve all fallen victims to some type of event where a breach of security has been experienced.

Nonetheless, perhaps Sidewalk’s greatest contribution is its ability to demonstrate that a low-cost, highly distributed IoT network is possible without significant investments in network infrastructure.
And the fact that they can easily leverage their own devices, particularly the millions of Echo devices that have been sold to date, could once again prove disruptive to the telecommunications industry putting further pressure on traditional operators to remain relevant in a rapidly changing services market.

Maybe it will work and maybe it won’t. But as the saying goes: Be brave enough to suck at something new.

Teresa Mastrangelo

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