6 ms·

> I think it's quite likely that sooner or later we will have 5G networks with intra-services running as edge-services, providing us low-latency. Noob question

> I think it's quite likely that sooner or later we will have 5G networks with intra-services running as edge-services, providing us low-latency. Noob question, sorry, but: Why not Wifi?

Jhsto 6y ago
LTE (and 5G on 3.6Ghz, I guess) signal can cover many kilometers. The protocols are built to be more reliable (a phone keeps a tab of access points to which it can quickly hop if access to one base station is lost) and the licensing ensures that there cannot be spectrum suffocation at any time, which is quite common in bigger cities with WiFi.
- g_p 6y ago
  Seamless handovers are definitely key to mobile networks, and much of the 3GPP technology is designed around this. Spectrum licensing is more about ensuring exclusive use of spectrum - in a busy built up area (less common during current times hopefully), you'll still suffer from "spectrum suffocation" like with WiFi - if you ever experienced data stalling where your phone indicated a signal, but weren't getting any actual traffic through, you were on a cell that was hitting the limits of the air interface capacity. The nice part of cellular networks is that you can add more base stations using other licensed spectrum the operator has, in order to get more capacity. So with 3.5 GHz 5G bands, and wider cell widths supported, these can take some of the load in busy places. Otherwise the alternative is to deploy more base stations with lower power on each, to better and more effectively reuse the spectrum. Since the same operator runs all the equipment on their own spectrum, they can coordinate this much more effectively than ad-hoc multi operator WiFi in a congested area. The downside is the vastly increased complexity of a cellular solution (the sheer number of pages of standards), and the "entrenched player lock-in" available to legacy telecoms operators who already hold spectrum.
  - matt9j 6y ago
    In addition to just the total amount of spectrum, coordinated scheduling between towers in the cellular standards helps with cooperative management of interference. Some of this is just now happening in 802.11ax, but without the high-speed non-microwave connections that celltowers in dense areas enjoy to coordinate over. 5G-NR also allows coordinated multipoint transmission, which you can think of kind of like MIMO but from multiple towers instead of just multiple antennas on the same tower. I don't know if this would ever be feasible in consumer WiFi equipment due to the challenges of synchronizing clocks across the different APs.
14k12j41j211 6y ago
Mobile networks allow seamless switching of cells. If you're on a call while in the car, your connections won't drop and ideally you wouldn't loose a single packet. Network and smartphone monitor nearby cells. If you're just about to switch the cell because the quality becomes too bad, everything is already being prepared in the next cell.
- Nextgrid 6y ago
  With proper configuration, Wi-Fi can do this too. Things like 802.11r, 802.11k, etc allow a station to roam between access points near-instantly.
  - ex3ndr 6y ago
    MacOS + UniFi actually have seamless reconnection.
ksec 6y ago
Because 5G, or even 4G LTE is still technically superior to even latest WiFi 802.11ax.
- superkuh 6y ago
  Only slightly. Most of the difference is telcos paying the $$$ to get their antennas up high with line of sight.
  - ksec 6y ago
    Well Not really. 5G / 4G are far better in noisy, complex multi user environment. You could get higher bandwidth from 4G / 5G then you could in best case WiFi scenario ( Line of Sight ) with equal spectrum. 802.11ax was basically moving some of the LTE tools over to WiFi ( OFDMA ) and completely failed. And pushing back some intended features to 802.11be.

> I think it's quite likely that sooner or later we will have 5G networks with intra-services running as edge-services, providing us low-latency. Noob question, sorry, but: Why not Wifi?

Jhsto 6y ago

LTE (and 5G on 3.6Ghz, I guess) signal can cover many kilometers. The protocols are built to be more reliable (a phone keeps a tab of access points to which it can quickly hop if access to one base station is lost) and the licensing ensures that there cannot be spectrum suffocation at any time, which is quite common in bigger cities with WiFi.

g_p 6y ago
Seamless handovers are definitely key to mobile networks, and much of the 3GPP technology is designed around this. Spectrum licensing is more about ensuring exclusive use of spectrum - in a busy built up area (less common during current times hopefully), you'll still suffer from "spectrum suffocation" like with WiFi - if you ever experienced data stalling where your phone indicated a signal, but weren't getting any actual traffic through, you were on a cell that was hitting the limits of the air interface capacity. The nice part of cellular networks is that you can add more base stations using other licensed spectrum the operator has, in order to get more capacity. So with 3.5 GHz 5G bands, and wider cell widths supported, these can take some of the load in busy places. Otherwise the alternative is to deploy more base stations with lower power on each, to better and more effectively reuse the spectrum. Since the same operator runs all the equipment on their own spectrum, they can coordinate this much more effectively than ad-hoc multi operator WiFi in a congested area. The downside is the vastly increased complexity of a cellular solution (the sheer number of pages of standards), and the "entrenched player lock-in" available to legacy telecoms operators who already hold spectrum.
- matt9j 6y ago
  In addition to just the total amount of spectrum, coordinated scheduling between towers in the cellular standards helps with cooperative management of interference. Some of this is just now happening in 802.11ax, but without the high-speed non-microwave connections that celltowers in dense areas enjoy to coordinate over. 5G-NR also allows coordinated multipoint transmission, which you can think of kind of like MIMO but from multiple towers instead of just multiple antennas on the same tower. I don't know if this would ever be feasible in consumer WiFi equipment due to the challenges of synchronizing clocks across the different APs.

14k12j41j211 6y ago

Mobile networks allow seamless switching of cells. If you're on a call while in the car, your connections won't drop and ideally you wouldn't loose a single packet. Network and smartphone monitor nearby cells. If you're just about to switch the cell because the quality becomes too bad, everything is already being prepared in the next cell.

Nextgrid 6y ago
With proper configuration, Wi-Fi can do this too. Things like 802.11r, 802.11k, etc allow a station to roam between access points near-instantly.
- ex3ndr 6y ago
  MacOS + UniFi actually have seamless reconnection.

ksec 6y ago

Because 5G, or even 4G LTE is still technically superior to even latest WiFi 802.11ax.

superkuh 6y ago
Only slightly. Most of the difference is telcos paying the $$$ to get their antennas up high with line of sight.
- ksec 6y ago
  Well Not really. 5G / 4G are far better in noisy, complex multi user environment. You could get higher bandwidth from 4G / 5G then you could in best case WiFi scenario ( Line of Sight ) with equal spectrum. 802.11ax was basically moving some of the LTE tools over to WiFi ( OFDMA ) and completely failed. And pushing back some intended features to 802.11be.