The Disjunction Between Present-Day Wireless Technologies


So when are we going to start seeing a trend of connected cars that have built-in LTE radios and WiFi? Or trains? Or busses? Or even taxis?

I’ve already seen this rolled out in a few places around the world, such as specific train rides from airports to city centers, or certain tour busses in certain cities, but  I’m talking about a lot more than just that.

Don’t get me wrong, I understand the convenience of having LTE deployed on the mobile phone. It’s nice to always be connected because you never know when you’re gonna get that important email, or that news notification, or even that phone call (when VoLTE-type technologies finally make it to prime time). I’m not even against this, but then again, we’ve seen it in many other tech trends, that idea of tiering different technologies.

In such a case, as this one, tiered wireless systems would be classified to identify different wireless technologies for different coverage scales. Most people don’t know this, Bluetooth is classified as a Personal Area Network (PAN) technology, i.e. it is meant to provide sufficient coverage for your personal space—does this ring a bell with the current IoT craze?

So we have Bluetooth for PANs, next we have WiFi, which is a Wireless Local Area Network (WLAN) technology; “Wireless” and “Local”! Linguistically speaking, this implies an area that covers a certain location, e.g. an apartment, a villa, a building, a park, and dare I say, a bus, a subway car, a taxi, your personal sedan?

Then finally, we have LTE (and 3G/HSDPA, and upcoming 5G technology) which is classified as a Wireless Wide Area Network (WWAN). “Wide Area”? Yeah, that’s just a common term in the networking world that we use for city-scale and country-scale deployments of a network service. Are you beginning to see the trend here?

Call me old-fashioned, but I like structuring such systems so they standardize deployment scenarios and create a homogenous and converged infrastructure. We’ve already seen this integration take place between wired (Ethernet) LANs and wireless (WiFi) LANs. Almost all enterprise networks and home networks today have integrated Ethernet and WiFi technologies; Cisco calls this Unified Access connectivity.

Now let’s think concentric circles. You have your PAN, where you interconnect your smartphone with your smart watch, heart rate sensor, fitness sensor, and what have you. Your smartphone or tablet (or both) connect to the local WiFi network—essentially they act as Internet gateways to these other devices in your PAN. The local WiFi network is then wired back to a wired internet connection or a WWAN connection (e.g. LTE) depending on the deployment scenario; in a bus (very mobile) for example, you would have it connected to an LTE radio, which then connects to the service providers’ networks.

What do we get from all of this?

Well, one of the biggest advantages of tiering technologies is the level of control that you get at each layer. Imagine you are sitting in a double decker tour bus in London, and you are connected to its WiFi network; two things happen here:

  1. The wireless signal integrity is from your phone to the local WiFi only, and then again from the bus’s LTE radio to the closest LTE base station.
  2. The power consumption on your smartphone is a lot more deterministic (and lower), as your phone’s environment is hardly changing; it is only connected to the local WiFi which is relatively stationary.
  3. The bus can be outfitted with radio+antenna technology that is optimized for movement and varying signal conditions; a lot more sophisticated and advanced than what a smartphone can be outfitted with.
  4. The bus’s radio system can be power enhanced and tuned, as the bus can output a lot more power than your measly little iPhone.
  5. The service providers’ base stations have to deal with a lot less “clients”; on this bus alone the 20-30 passengers will no longer be connected directly to the base station, only the bus will be (simpler and less crowded work for the scheduler)
  6. Client bandwidth commitments can be dealt with at upper control-plane layers.

Another advantage is the fact that you are breaking down a very large system into smaller subsystems that can each be optimized incrementally and individually. This leads to cheaper and more gradual upgrade road maps for systems. Imagine you live in an apartment building with a similar topology; you connect to the building’s WiFi, and roam throughout, while this is wired back to a master LTE radio system that connects back to the service provider’s WWAN network:

  1. Antennas can be deployed at the roof with clearer waveguide paths from/to the service provider’s base stations.
  2. The service provider doesn’t need to overcompensate/over-size their infrastructure to make sure that their signal is making its way into your house (through concrete walls).
  3. The service provider doesn’t need to worry about indoor signal booster/repeater systems that also have non-linear scaling traits; it rather becomes a bandwidth management issue (upper control-plane).
  4. With technology evolution, the service provider only has to worry about improving antenna-to-antenna data paths, and not antenna-to-device. This also makes it easier to decommission older technologies without having to worry about consumer devices being compatible. Seriously now, your phone runs 2G, 3G and 4G… overkill much?
  5. Don’t you think number 4 would also imply a more effective cost-model for service providers and their infrastructures?
  6. Infrastructure costs of excavating to run ducting to buildings with fiber optic cables (as much as I love them, they require lots of installation overhead) can be virtually eliminated.

With all that’s been said, and with the fact that using wireless technology today has become quite commonplace, even so when you travel. You’ve seen all the advantages that can be achieved (and there are even more that weren’t even touched upon) by tiering wireless network technologies. 

Using WWAN technologies such as LTE, and the upcoming 5G, as more of an infrastructure/backend technology, while integrating them with WiFi at the access layer can really prove to be a win-win for all stakeholders—the consumers, the service providers, the smartphone manufacturers, they all have a lot to gain from such an approach.

What are your thoughts, please feel free to share.

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