4 ms·

4G LTE has dramatically higher system spectral efficiency (in bits/Hz) compared to 2G - over 100x [0]. That's why 2G is getting decommissioned in favor of LTE (

by ac29 7y ago

4G LTE has dramatically higher system spectral efficiency (in bits/Hz) compared to 2G - over 100x [0]. That's why 2G is getting decommissioned in favor of LTE (and 5G). NB-IoT is probably where your application would go these days. Bi directional communication, cheap chips, and data plans around $10/device/year for 12MB [1], which is a lot of short messages (though things like OTA firmware updates might be painful). [0] https://en.wikipedia.org/wiki/Spectral_efficiency https://en.wikipedia.org/wiki/Spectral_efficiency [1] https://www.twilio.com/wireless/narrowband https://www.twilio.com/wireless/narrowband

ansible 7y ago
Spectral efficiency is super important. Especially with IoT, because there are going to be so many devices. Trying to do that with old pager network bandwidth would quickly overload the network.
- Retric 7y ago
  IoT is really several different kinds of devices. Many of which are extremely low bandwidth. When you’re talking a few per hour, spectrum bandwidth is simply a non issue.
  - icebraining 7y ago
    A single device may be low bandwidth, but what about when you have thousands of such devices in a single apartment building?
    - Retric 7y ago
      100 bits per hour * 10,000 devices = 278 bits per second. That’s significantly less than the equivalent of a single cellphone per apartment building.
      - magduf 7y ago
        You're assuming they all spread out their communications evenly. What if they all want to send out a status update message on the hour?
        Retric 7y ago
        That one of the reasons for the random delays are for in most network protocols. However, 10,000 devices sending 100 bits over say 10 seconds is still only 100kbps.
- jake_morrison 7y ago
  I am not talking about using the pager network for that, I am talking about the 2G network. I am not opposed to using more efficient network protocols, more that we are endlessly replacing old technologies with completely new systems. The selling point of 3G/4G/5G has been that they will have more bandwidth, so people can watch videos or use self driving cars. What is more interesting to me is embedding cheap low-bandwidth smarts in more devices. The costs of the new and immature hardware gets in the way of that.
  - icebraining 7y ago
    Handling a large number of IoT devices has definitively been one of the major selling points of 5G.
  - Foivos 7y ago
    One of the goals of 4G/5G is to allow for the coexistence of high bandwidth devices with IoT. I agree that at this point the cost of cellular IoT is higher than it should and the technology is immature. In the long term though, it would be a better choice than keeping a 2G network.
  - zamadatix 7y ago
    > The selling point of 3G/4G/5G has been that they will have more bandwidth, so people can watch videos or use self driving cars. In the cellphone commercial sure but in technical reality it's about device density. There is only one set of airspace and only certain chunks are useful for where we want to communicate; getting the most devices able to communicate has been the leading driver of RF planning and design for quite some time now. Bandwidth usually materializes out of a combination of more "slots" to talk and simply not using restrictions needed for 20 year old consumer hardware.
jake_morrison 7y ago
If I am sending 100 bytes, then spectral efficiency is not my biggest problem. NB-IoT is fine, I will have to use it. The cost of 4G/5G chips is a lot higher than older generations, to say nothing of what would happen if anyone can make chips. Everyone just wants to sell me something new, because that's how they make money. When 3G came out all the telecoms were excited to sell video, as it would give higher average revenue per user. Turns out people don't want to pay more. We get faster networks but keep the same price per GB, so with 5G I will be able to blow through my monthly bandwidth in 60 seconds. And that assumes that the carriers have the backbone capacity.
- ac29 7y ago
  You don't need a full fledged 4G chip for NB-IoT - something like Quectel BC66 would work. Its ~€10/each for QTY250 [0], or €29 for QTY1 on a Arduino compatible dev board [1]. Ublox has a similar product for a similar price [2]. [0] https://www.avnet.com/shop/emea/products/quectel-wireless-solutions/bc66nb-04-std-3074457345635728059 https://www.avnet.com/shop/emea/products/quectel-wireless-so... [1] https://www.tekmodul.de/produkt/bc66-dvk/ https://www.tekmodul.de/produkt/bc66-dvk/ [2] https://www.u-blox.com/en/product/sara-r4-series https://www.u-blox.com/en/product/sara-r4-series
- spookthesunset 7y ago
  Spectral efficiency may not be an issue for you but it sure as hell is an issue for your carrier. What people are telling you is that 5G is more than just a plot to sell you YouTube streaming. It is the only way carriers can scale the mobile network to meet its growing needs. There are only so many ways you can cram more people into a shared medium like the RF spectrum....
Foivos 7y ago
LTE-M / LTE cat.0 would be the ideal replacement for a pager. NB-IoT is not meant for mobility. NB-IoT has cell reselection mechanisms, so you can connect to a different base station, but the process is very energy demanding. It is meant to be used rarely, for example when a closer base station activates. Also, firmware updates for these devices are a few KB typically and occur maybe once every 6 months. 12 MB per year should be enough.

by ac29 7y ago

ansible 7y ago

Spectral efficiency is super important. Especially with IoT, because there are going to be so many devices. Trying to do that with old pager network bandwidth would quickly overload the network.

Retric 7y ago
IoT is really several different kinds of devices. Many of which are extremely low bandwidth. When you’re talking a few per hour, spectrum bandwidth is simply a non issue.
- icebraining 7y ago
  A single device may be low bandwidth, but what about when you have thousands of such devices in a single apartment building?
  - Retric 7y ago
    100 bits per hour * 10,000 devices = 278 bits per second. That’s significantly less than the equivalent of a single cellphone per apartment building.
    - magduf 7y ago
      You're assuming they all spread out their communications evenly. What if they all want to send out a status update message on the hour?
      - Retric 7y ago
        That one of the reasons for the random delays are for in most network protocols. However, 10,000 devices sending 100 bits over say 10 seconds is still only 100kbps.
jake_morrison 7y ago
I am not talking about using the pager network for that, I am talking about the 2G network. I am not opposed to using more efficient network protocols, more that we are endlessly replacing old technologies with completely new systems. The selling point of 3G/4G/5G has been that they will have more bandwidth, so people can watch videos or use self driving cars. What is more interesting to me is embedding cheap low-bandwidth smarts in more devices. The costs of the new and immature hardware gets in the way of that.
- icebraining 7y ago
  Handling a large number of IoT devices has definitively been one of the major selling points of 5G.
- Foivos 7y ago
  One of the goals of 4G/5G is to allow for the coexistence of high bandwidth devices with IoT. I agree that at this point the cost of cellular IoT is higher than it should and the technology is immature. In the long term though, it would be a better choice than keeping a 2G network.
- zamadatix 7y ago
  > The selling point of 3G/4G/5G has been that they will have more bandwidth, so people can watch videos or use self driving cars. In the cellphone commercial sure but in technical reality it's about device density. There is only one set of airspace and only certain chunks are useful for where we want to communicate; getting the most devices able to communicate has been the leading driver of RF planning and design for quite some time now. Bandwidth usually materializes out of a combination of more "slots" to talk and simply not using restrictions needed for 20 year old consumer hardware.

jake_morrison 7y ago

If I am sending 100 bytes, then spectral efficiency is not my biggest problem. NB-IoT is fine, I will have to use it. The cost of 4G/5G chips is a lot higher than older generations, to say nothing of what would happen if anyone can make chips. Everyone just wants to sell me something new, because that's how they make money. When 3G came out all the telecoms were excited to sell video, as it would give higher average revenue per user. Turns out people don't want to pay more. We get faster networks but keep the same price per GB, so with 5G I will be able to blow through my monthly bandwidth in 60 seconds. And that assumes that the carriers have the backbone capacity.

ac29 7y ago
You don't need a full fledged 4G chip for NB-IoT - something like Quectel BC66 would work. Its ~€10/each for QTY250 [0], or €29 for QTY1 on a Arduino compatible dev board [1]. Ublox has a similar product for a similar price [2]. [0] https://www.avnet.com/shop/emea/products/quectel-wireless-solutions/bc66nb-04-std-3074457345635728059 https://www.avnet.com/shop/emea/products/quectel-wireless-so... [1] https://www.tekmodul.de/produkt/bc66-dvk/ https://www.tekmodul.de/produkt/bc66-dvk/ [2] https://www.u-blox.com/en/product/sara-r4-series https://www.u-blox.com/en/product/sara-r4-series
spookthesunset 7y ago
Spectral efficiency may not be an issue for you but it sure as hell is an issue for your carrier. What people are telling you is that 5G is more than just a plot to sell you YouTube streaming. It is the only way carriers can scale the mobile network to meet its growing needs. There are only so many ways you can cram more people into a shared medium like the RF spectrum....

Foivos 7y ago

LTE-M / LTE cat.0 would be the ideal replacement for a pager. NB-IoT is not meant for mobility. NB-IoT has cell reselection mechanisms, so you can connect to a different base station, but the process is very energy demanding. It is meant to be used rarely, for example when a closer base station activates. Also, firmware updates for these devices are a few KB typically and occur maybe once every 6 months. 12 MB per year should be enough.