T-Mobile said San Francisco regulators aren't moving at the speed of 5G. In a new lawsuit filed this week against the city and county's department of building inspection, T-Mobile alleges that San Francisco officials haven't acted quickly enough on its requests to modify and upgrade its cell sites with 5G."Particularly in light of the significant increase in demand driven by the COVID-19 pandemic, which has emphasized the importance of new technologies, such as 5G, distance learning and a robust network, T-Mobile needs to modify and upgrade many of its existing wireless installations in the city of San Francisco," T-Mobile wrote in the lawsuit.T-Mobile said it has "encountered significant delays" in getting approvals for 27 different cell site upgrade applications. "The city had not acted on the applications even by late October 2020, well over 60 days after they were submitted," the operator wrote, pointing to the FCC's new "shot clock" that requires cities to act on 5G operators' cell site upgrade applications within 60 days."Congress and the FCC have sought to eliminate barriers and streamline the regulatory review process to facilitate deployment and modification of wireless communications infrastructure necessary for the efficient creation of new and upgraded wireless networks such as 5G," T-Mobile explained in the filing.Officials from San Francisco's building department did not immediately respond to questions about the lawsuit. T-Mobile is in the early stages of a five-year, $60 billion 5G network upgrade program.Racing over objectionsThe lawsuit is just the latest development in a long-running legal battle between the wireless industry and some local officials over how exactly 5G cell towers should be built. On the industry side, operators, vendors and some federal policymakers argue that 5G is important to the economy and national security and therefore requires nationwide regulations to make it easier and quicker for operators to construct 5G cell sites all over the country. On the other side stand some local officials who bristle at the notion that they can't have complete control over the construction or modification of cell towers in their own neighborhoods.The issue came to a head in 2018, when the FCC approved rules intended to limit the amount of money cities could charge wireless network operators for the installation of small cells. The rules also require cities to move quickly on small cell installation requests.Dozens of cities and city representatives – ranging from Seattle to Atlanta to Dallas to the League of California Cities – filed a lawsuit to block the rules. However, just a few months ago, a federal appeals court mostly upheld the FCC's rules.Indeed, the FCC in June voted again to clarify and strengthen its rules around the issue, specifically concerning when the 60-day shot clock for local review begins. Those new guidelines sit at the heart of T-Mobile's lawsuit. "The city has failed to act on T-Mobile's applications," the operator complained.To be clear, T-Mobile isn't the only operator who has turned to the courts to speed up its network's rollout. Verizon and others have been tied to similar legal efforts around the country.Permitting woes remainDespite the FCC's new rules and other legislation on the topic at the state level, some big players in the space continue to see lengthy permitting timelines. For example, executives from Crown Castle have said they're still allocating 18-36 months to construct a small cell, which is essentially a mini cell tower that can sit atop a building or light pole."The majority of that [18-36 months] being zoning, permitting and utility work that has to be done," explained Crown Castle CFO Dan Schlanger during a recent investor event, according to a Seeking Alpha transcript.Crown Castle has emerged as an important bellwether in the space because it is the only major public cell tower company to fully embrace the small cell sector. While its peers like American Tower and SBA Communications continue to mostly focus on large, "macro" towers, Crown Castle is working to construct thousands of new small cells, putting it in the heart of the permitting and zoning issue. Crown Castle currently operates around 70,000 small cells across the country, and has been working on switching on around 10,000 small cells per year. The company argues that the US market will eventually need more than 1 million total cell sites to support full-blown 5G networks.