Wireless networks have finite capacities. If enough users try to send data over a network at the same time, the network will become congested and deliver slower speeds.
Not all users will see the same decreases in speeds during congestion. Prioritization policies govern how different people on a network are affected by congestion. In many cases, subscribers with premium service plans will be prioritized ahead of subscribers on low-cost plans. When low-priority subscribers are experiencing sluggish speeds during congestion, they’re often described as being “deprioritized.”
There’s a shocking lack of public information about prioritization policies. Over the last year, I’ve dug into legalese to figure out how major carriers prioritize different plans, looked into the technical mechanisms behind prioritization, and spoken with industry experts. I’ve created what I believe is some of the most detailed content about prioritization policies among carriers in the U.S. Despite all that, I regularly find myself confused about prioritization.
Vague deprioritization disclosures
Carriers typically disclose the possibility of deprioritization in fine-print statements along these lines:
During periods of congestion, subscribers on this plan may experience data speeds slower than those received by other subscribers on the network.
Disclosures tend to be vague. Carriers almost never discuss the frequency of deprioritization, the severity of speed decreases, or the locations where subscribers will be especially prone to deprioritization.
Is deprioritization a big issue for low-cost plans?
Mobile virtual network operators (MVNOs) are often prohibited from discussing specific terms of their arrangements with host networks. In many cases, MVNOs can’t even make clear statements about which networks they operate over. In preparation for this post, I talked with a few people who are knowledgeable about the MVNO industry. None of them wanted to be quoted.
The general view among participants on online forums about the wireless industry is that almost all MVNO subscribers are deprioritized. However, there are competing claims. The MVNO Ting published a blog post titled Do MVNOs get second class cell service? The post explicitly states that Ting subscribers on Sprint’s network have priority on-par with typical Sprint subscribers. Ting’s post also seems to carry an implicit suggestion that subscribers using other MVNOs are usually not deprioritized:
The truth of the matter is, Sprint’s MVNO contract states that Sprint must provide its Customer MVNOs with service parity to traditional Sprint wireless voice and data service. It’s all laid out in very clear terms…The problem is, the discussion of whether or not carriers throttle and traffic shape MVNOs on their network takes on a conspiratorial tone online. I know, it’s shocking! Suppositions get accepted as fact. Assumptions leap off from suppositions and next thing you know, it’s all true because someone read it on the Internet. Hopefully this helps to dispel the myth.
Wirecutter has written about prioritization, and it looks like the company reached out to a handful of carriers about their policies (emphasis mine):
[Some carriers] prioritize their own customers over third-party prepaid traffic, as happens with the Metro by T-Mobile subsidiary. A T-Mobile spokesperson confirmed that policy, saying that although postpaid and prepaid T-Mobile service have the same priority, Metro by T-Mobile and other resellers ‘may notice slower speeds in times of network congestion’…However, AT&T, Sprint, and Verizon told us that they don’t impose any such prioritization.
I don’t buy it. Xfinity Mobile, a popular Verizon reseller, explicitly acknowledges deprioritization:
In times of congestion, your data may be temporarily slower than other traffic.
Verizon makes it clear that its own prepaid subscribers will be deprioritized during congestion. Verizon’s flanker brand, Visible, also deprioritizes subscribers’ data.
While these facts don’t rule out the possibility that Verizon gives high-priority access to some resellers, I’d be awfully surprised if subscribers with Verizon resellers typically have higher priority than a large portion of Verizon’s own subscribers.
Does deprioritization matter?
There are a lot of reasons people experience slow speeds, and people may be too quick to assume that deprioritization is the source of lousy speeds. Unfortunately, I don’t know of any publicly available data that sheds light on how often deprioritization causes trouble for consumers. As far as tell, drive tests assessing network performance typically use high-priority services. I’d be interested to see how assessments would come out tests were run with low-priority services.
Sharing better information
I’m aiming to offer the best public-facing content about prioritization policies. If you work in the wireless industry and would like to talk publicly or privately about prioritization policies, please reach out.