Priority On Cell Networks
By Christian SmithPrioritization policies determine how network operators manage traffic on a cell network when capacity is constrained. Rather than treating all subscribers equally, network operators give preferential treatment to some users.
Jump to Network-Specific Policies:When Priority Matters
Cell networks usually have more capacity than they need. Prioritization policies policies only matter when the demand for a network's bandwidth exceeds what's available.
A concert or similar event can cause short-term congestion. Congestion can also be a problem on an ordinary day in areas where network infrastructure is insufficient.
Premium Data & Deprioritization
Cell carriers may use the phrase "premium data" to indicate data that's given high priority. A subscriber might be described as "deprioritized" if they're demoted to a priority level behind the typical subscriber.
QCI Values
On 4G LTE networks, Quality Of Service Class Identifiers (or QCI values) determine the priority level given to data.
Most data use is associated with QCI or 5QI values between 6 and 9. In that range, lower values are associated with higher priority service on a given network.
🤓 Note: Voice calls and atypical forms of data use may be associated with values below 6. Low values may confer especially high priority or guaranteed data speeds.
For in-the-weeds details about QCI values, see the 3GPP publication Policy and charging control architecture.
5QI Values
5QI, a mechanism similar but not exactly equivalent to QCI, is used with 5G networks.
At the moment, 5QI values we've observed match the QCI values observed for the same service. That may not always remain true. While the rest of this page generally refers to QCI values, Broadband Map monitors for discrepancies between the two values.
🤓 Note: Apart from 5QI and QCI values, other mechanisms could be used to affect data priority, but these don't seem to be widely used in the US market.
Prioritization By Network
Taken together, legal disclosures, standards docs, and QCI tests provide outlines of how prioritization works on each major network. Those outlines, along with QCI/5QI test results, are shared below. Huge thanks to Reddit user Ethrem for working with Broadband Map to keep the testing up to date.
⚠️ Note: QCI and 5QI values should be interpreted in the context of a given network. A QCI of 8 is associated with good priority on Verizon's network but low priority on T-Mobile's network.
Icons
When discussing the QCI of specific plans, I use the following icons:
- Confirmed by a recent test we ran- Found in an old test we ran or found in a test run by someone I consider credible
- Inferred with high confidence
- Inferred with moderate confidence
List Filters
AT&T's Network
Most data use on AT&T's network falls into one of three buckets:
- High Priority (QCI 7) - Select premium plans, customers with AT&T Turbo
- Decent Priority (QCI 8) - Most premium and semi-premium plans, some MVNOs
- Low Priority (QCI 9) - Most budget-friendly plans, some MVNOs
QCI 6 may be available to some high-end business plans and certain first responders on AT&T FirstNet.
Especially High Priority on AT&T
Some data traffic on AT&T's network has especially high priority. Even on eligible services, this especially high priority may only be available for specific types of traffic or in specific scenarios.
- AT&T FirstNet Plans[note]
- AT&T Business Plans with Fast Track[note]
QCI 7 - High Priority on AT&T
- Business Unlimited Premium
- Subscribers with the AT&T Turbo add-on
- AT&T Unlimited Elite
QCI 8 - Decent Priority on AT&T
- AT&T Unlimited Premium PL
- AT&T Unlimited Extra EL
- AT&T Internet Air for Business Standard plans
- Cricket More (Cricket's fancier unlimited plan)
- Most of Cricket's fixed-data plans[note]
- Consumer Cellular
- PureTalk
- H2O
- US Mobile Unlimited Premium on the Dark Star network
- Other US Mobile Dark Star plans with priority data add-on
- Some other MVNOs
- AT&T Unlimited Extra
QCI 9 - Low Priority on AT&T
- AT&T Unlimited Starter SL
- AT&T Business Unlimited Standard
- AT&T Internet Air (Residential)
- AT&T Internet Air for Business Standard plans
- Cricket Core (Cricket's base unlimited plan)
- Some MVNOs
- Customers exceeding allotted priority data on other plans /
- AT&T Unlimited Starter
T-Mobile's Network
Most data use on T-Mobile's network falls into one of four buckets:- High Priority (QCI 6) - Most T-Mobile-branded plans
- Mediocre Priority (QCI 7) - Essentials plans, Most MVNOs
- Low Priority (QCI 8) - Largely used for on-device hotspot use
- Lowest Priority (QCI 9) - Largely heavy data users & internet plans
Especially High Priority on T-Mobile
- Plans with T-Priority
QCI 6 - High Priority on T-Mobile
- T-Mobile Experience More
- T-Mobile Experience Beyond
- T-Mobile Connect
- T-Mobile Business plans (nearly all of them)
- Google Fi
- Most other T-Mobile-branded plans (prepaid and postpaid) not listed elsewhere /
- T-Mobile Go5G Next
- T-Mobile Go5G Plus
- T-Mobile Go5G
- Magenta
QCI 7 - Mediocre Priority on T-Mobile
- T-Mobile Essentials /
- T-Mobile Essentials Saver
- Metro
- Mint Mobile
- US Mobile on the Light Speed network
- Most MVNOs /
QCI 8 - Low Priority on T-Mobile
- Most on-device mobile hotspot use
- Some data-only plans
QCI 9 - Lowest Priority on T-Mobile
- Customers exceeding their allotted priority data /
- MI30 Plan
Verizon's Network
Data used on Verizon's network generally falls into one of two buckets:- High Priority (QCI 8) - Most of Verizon's premium postpaid plans, the Visible+ plan, select MVNOs
- Low Priority (QCI 9) - Most of Verizon's prepaid plans, most plans from Verizon's flanker brands, most MVNOs
An even higher priority level (QCI 7) is available through Verizon Frontline, a service for first responders.
Especially High Priority on Verizon
- Verizon Frontline plans
Allegedly, at least some Verizon Frontline plans for first responders have QCI 7 data. I've never tested one of these plans myself.
QCI 8 - High Priority on Verizon
- Verizon Unlimited Ultimate
- Verizon Unlimited Plus
- Verizon Prepaid Unlimited Plus
- Visible+ Plan
- Spectrum Mobile
- US Mobile Warp (5G-capable devices)
- Xfinity Mobile By-The-Gig plans
- Verizon Play More Unlimited
- Verizon Do More Unlimited
- Verizon Get More Unlimited
QCI 9 - Low Priority on Verizon
- Verizon Unlimited Welcome
- Verizon Prepaid Unlimited
- Verizon Prepaid 15GB
- Visible Base Plan
- US Mobile Warp (4G-only devices)
- Customers exceeding their allotted priority data on other plans /
- Verizon Start Unlimited
Appendix
Other Prioritization Mechanisms
Broadband Map aims to track the evolution of network operators' approaches to prioritization. Today, QCI & 5QI values are the primary mechanisms used to handle prioritization. However, other mechanisms can be used.
AT&T's Fast Track may, at least partially, rely on a non-QCI mechanism that responds differently for different types of traffic.
As 5G Standalone networks become more common, carriers may increasingly offer services that rely on network slicing. With slicing, a portion of network resources can be carved out for a specific use case or set of customers—forming the cellular equivalent of an express lane on a highway.
T-Mobile is trialing a form of network slicing for first responders and emergency services via its T-Priority product. Broadband Map is not aware of slices being used for consumer plans.
Additional mechanisms may be used for network and congestion management. For example, speed throttling or video shaping are commonly used to reduce the bandwidth consumed by certain network users. While these mechanisms affect cellular performance, Broadband Map doesn't consider them relevant to prioritization.
Notes
- I'm unsure what's going on with TracFone brands. Reports of test results I've seen online have conflicted with my own test results. Additionally, Verizon's purchase of the brands may lead to changes.
- My hunch is that Xfinity's current unlimited plans are both QCI 8, but I'd like to see a recent test.