The Vision of Next Century Cities

Next Century Cities is an organization comprised of 166 mayors of cities that have the mission statement to make sure that all of their citizens have access to fast, affordable and reliable Internet access. The members range from small towns to NFL cities. They recently published their 2017 Policy Agenda that highlights the issues that they think are the biggest impediments to meeting their broadband goals. These goals are worth some thought since they differ from the wish list of most other stakeholders in the industry.

Restore Local Authority. Cities want to have a hand in finding their own broadband solutions and they don’t want to be restricted by state or federal law from doing so. I would note that the vast majority of cities do not want to be a retail ISP, but they still want to have the ability to make the investments needed to meet their broadband goals. They want to be able to form meaningful public-private partnerships. And more than anything else they want the legal authority to find broadband solutions.

Competition in Multi-Dwelling Units (MDUs). Cities with any significant percentage of citizens living in MDUs are concerned that those citizens are often not getting the same quality broadband products or having the same array of choice as single family homes. For example, even where fiber has been built, overbuilders often skip MDUs that present construction or operational issues. Cities are also still concerned about the proliferation of exclusive contracts between MDU owners and ISPs.

Anti-Monopoly and Competition. Mayors are concerned by what they see as shrinking competition. In many cities the cable companies have won the broadband battle against the telco. Where there are no significant third-party fiber overbuilders the mayors see broadband becoming a monopoly product. The cities generally are against the mergers of gigantic ISPs.

High-Quality Low-Income Internet Access. Cities are still looking for ways to solve the digital divide. They understand that there is a significant percentage of the population that doesn’t have broadband because they can’t afford it. They are currently dismayed by what they perceive as the FCC walking away from the Lifeline program that can subsidize broadband service in low income households.

Small Cell/5G/DAS. Cities are grappling with how to best foster and physically accommodate the coming proliferation of wireless transmitters that will be spread through the community to distribute 5G and millimeter wave spectrum. They are anticipating a host of new wireless broadband products, but they have concerns about how to deal with numerous wireless providers wanting to utilize the same key locations.

One Touch Make Ready. Cities are in favor of regulatory changes that make it easier for fiber overbuilders to get onto poles or into existing conduits. The ‘one touch make ready’ concept would greatly speed up the process and reduce the costs of the pole attachment process. It would give a new fiber builder the ability to more easily move wires of existing carriers to speed up the construction process. In cities with numerous existing carriers on pole lines the cost and time involved in gaining approval and of implementing the changes needed to accommodate a new carrier can be numbingly slow.

Infrastructure Investment. Cities want to be included in broadband infrastructure spending that might come from any federal infrastructure plan. They fear that any broadband money will be aimed only at rural areas and the FCC still estimates that there are more than 10 million people in large urban areas that can’t buy bandwidth that meets the FCC’s 25/3 Mbps threshold. And while smaller rural towns and cities might have broadband that meets that test, they often have older networks that are far below the standards of metropolitan areas.

Summary. Of all of the various stakeholder groups involved in broadband infrastructure deployment, cities the most focus on getting quality broadband to everybody. That focus puts them into opposition with incumbent ISPs on some issues. Experience shows us that cities are often more aligned with new overbuilders, at least to the extent that those ISPs don’t want to only cherry-pick the most lucrative customers in the city. Because of various state restrictions, cities vary widely in how much influence they have over broadband. But cities everywhere are the ones that determine some of the key processes in broadband deployment such as permitting and local construction practices. And that means that their goals must be recognized by anybody wanting to deploy new broadband in cities.

The Limitations of Cellular Data

SONY DSCIt’s hard these days to find anybody that is satisfied with the quality of data received over cellphones. A research report published by Aptelligent late last year showed that the US placed 10th in the world in overall cellular network performance, measured by the combination of reliability and speed. We all know that sometimes cellphone data is adequate, but can suddenly deteriorate to where you can’t load simple web pages. There are a number of factors baked into the cellular architecture that contribute to data performance. Following are a few of the key factors:

Data Power Drop-off. Cellular networks, by design, assume a massive drop-off of data speeds with distance. I don’t think most people understand how drastic the power curve is. Cellular companies show us bars to indicate the power of our connections – but these bars are not telling us a true story. The cellular architecture has a 100:1 data rate ratio from cell tower to the edge of the delivery area (generally a few miles). To provide an example, this means that if a cell site if designed to deliver 10 Mbps at the cell tower, that it will deliver only 1 Mbps at the mid-point of the cell tower range and only 0.1 Mbps at the edge.

Shape of the Cellular Footprint. It’s easy to think that there are nice concentric circles of cellphone signals propagating around cell towers. But nothing could be farther from the truth. If you go around any cell site and measure and plot the strength of signals you will find that the footprint of a cell tower looks a lot more like an amoeba, with the signal in some directions traveling a relatively short distance while in others it might travel much farther. If these footprints were static then engineers could design around the vagaries at a given cell site. But the footprint can change quite dramatically according to temperature, humidity and even the number of users concentrated in one portion of the footprint. This is why the delivery of broadcast wireless services is always going to more an art than a science, because the delivery footprint is constantly shifting, in many cases dramatically.

Proliferation of Antennas. Modern cellular networks have improved performance by significantly increasing the number of transmitting antennas on a cell tower (and also more receiving antennas in cell phones). This use of MIMO (multiple input, multiple-output) has produced a significant improvement for customers who are able to gain simultaneous signal from more than one transmitter. But there are two consequences of MIMO that actually decrease performance for some users. First, MIMO largely benefits those that are closest to the cell tower, and that means there are fewer quality connections available for those farther away from the cell tower. Second, MIMO has a secondary characteristic in that MIMO works best using cellular channels that are not-adjacent. And during time of heavy cellular usage this has the result of improving the signal strength in the MIMO channels but decreasing the strength of the other channels, again decreasing quality for customers that grab the weaker channels.

Impaired Hand Offs. Mobility is enabled in a cellular network when a customer is handed off from one cell site to the next while traveling. MIMO and other techniques that increase the signal to a given customer then make it more difficult for that customer to be handed to the next cell site. Hand offs were relatively error free when customers received a one channel signal from one transmitter, but now the quality of hand offs from one cell site to another can vary dramatically, resulting in more disconnects or drastic swings in the strength of connections.

Small-Cell Issues. All of the above issues will be compounded by the introduction of small-cells into the cellular network. In today’s cellular architecture a customer can only be handled by one cell tower at a time. Cellular networks don’t automatically assign the strongest connection to a customer, but rather the nearest available one. While small-cells will increase the opportunity to get a signal in a crowded environment, it also increases the chance of getting a poor connection, or of running into hand off issues for mobile customers.

2D Signal Propagation. Cell tower antennas are largely aimed to transmit close to the ground and do not waste signals by sending signals upwards in a 3D pattern. Anybody who has traveled to a big city and received poor signal on an upper floor of a tall hotel is familiar with this issue. The cellular signals are focused towards street level and not towards anybody higher. That’s not to say that you can’t get a cellular connection at the top of a highrise, or even in an airplane, but the vast majority of the connections (and the strongest connections) are aimed downward.

Crisis Propagation. Cell towers are arranged as an interconnected mesh. When something drastic happens to a given cell tower, such as losing power or being swamped with calls during an emergency, this not only shuts down the tower with a problem, but the problem cascades to nearby towers, often taking them out of service as well. This is similar to a rolling blackout in an electric grid. Carriers have been working on load balancing techniques to try to tamp down this problem, but it’s still relatively easy for a given cell tower to get overwhelmed and start a neighborhood and even regional cascade.

These issues all outline how complicated it is to design a great cellphone network. The above issues are worsened by the fact that in the US our cell sites were largely placed years ago to accommodate voice traffic and thus are not situated to instead provide optimum data traffic. But even a brand new cellular network designed to optimize data traffic would run into these same or different issues. It’s nearly impossible to design a cellular network that can handle all of the issues encountered in the real world. This makes me glad I’m not a cellular engineer.