November 2008 Archives

One of the smaller towns we tested in the NWBR was Rochelle, IL - a farming town of 10,000 people about 75 miles West of Chicago. In this case the ISP providing wireless internet service was the city itself through the Rochelle Municipal Utilities organization - along with power and water. It was an interesting experience going to the small office, right next store to the window where a citizen would pay their electric bill, to shop and sign up for Internet service ... with a variety of recommended CPE devices displayed on the wall. One the key items we argue about in building municipal networks is ownership - who should own and operate the network? And here in Rochelle was a rather good wireless network that was built by the town. And clearly where other options for broadband access offer poor performance or do not exist (The city started by offering dial-up Internet access and the wireless cellular carriers offer spectacularly poor wireless data products - the city’s networks offers roughly 20x the performance of the sadly 2G wireless cellular networks in the town.) This reminded me of the Rural Electrification Project (that had originally sponsored bringing electricity to Rochelle after WWII) - (from Wikipedia): In 1936 the Rural Electrification Act was enacted. Also, the Tennessee Valley Authority is an agency involved in rural electrification. The Rural Electrification Administration (REA), a former agency of the U.S. Department of Agriculture, was charged with administering loan programs for electrification and telephone service in rural areas. The REA was created in 1935 by executive order as an independent federal bureau, authorized by the United States Congress in 1936, and later in 1939, reorganized as a division of the U.S. Dept. of Agriculture. The REA undertook to provide farms with inexpensive electric lighting and power. To implement those goals the administration made long-term, self-liquidating loans to state and local governments, to farmers' cooperatives, and to nonprofit organizations; no loans were made directly to consumers. In 1949 the REA was authorized to make loans for telephone improvements; in 1988, REA was permitted to give interest-free loans for job creation and rural electric systems. By the early 1970s about 98% of all farms in the United States had electric service, a demonstration of REA's success. The administration was abolished in 1994 and its functions assumed by the Rural Utilities Service. The Rural Electrification Administration (REA) was an agency of the United States federal government created on May 11, 1935 through efforts of the administration of President Franklin D. Roosevelt. The REA's task was to promote electrification in rural areas, which in the 1930s rarely were provided with electricity due to the unwillingness of power companies to serve farmsteads. America lagged significantly behind European countries in rural electrification. Private electric utilities argued that the government had no right to compete with or regulate private enterprise, despite many of these utilities having refused to extend their lines to rural areas, claiming lack of profitability. Since private power companies set rural rates four times as high as city rates, this was a self-fulfilling prophecy.[1] Under the REA program there was no direct government competition to private enterprise. Instead, REA made loans available to local electrification cooperatives, which operated lines and distributed electricity. By 1939 the REA served 288,000 households, prompting private business to extend service into the countryside and to lower rates. By the end of the decade, forty percent of rural homes had power, up from around 10% in 1930. From 1949, the REA could also provide assistance to co-operative telephone companies. In ten years, rural electrification increased from 10% of rural homes to 40% by 1940. So why can’t we use this already successful model of the Rural Electrification Project as the basis for government deploying broadband, particularly in less developed areas? While some of the early attempts at municipal wireless were not considered successful (Philadelphia, for example) they had the clear effect of dropping the local cost of wired broadband access. Competition beyond the entrenched monopolies of DSL and cable is a good thing.

The Novarum team will be blogging here and we are re doing our web site to integrate the blog system.

It was clear from the beginning of the NWBr that the proper choice of client device makes all the difference in the complete system performance of a municipal wireless network ... and in particular the user experience. Cellular and pre-WiMax (and mobile WiMax when delivered) networks precisely specify the client and test its performance. These clients are much more rigorously controlled and, in general, have much high transmit power and better antennas with less noise than WiFi clients. In the process of the NWBR we have tested many client devices to see the effect of client devices on network performance - testing them in the same networks in the same locations, at the same time ... to more accurately assess the difference. We tested the following clients:

1. Standard 802.11g laptop client - approximately 30 mW output power
2. A high power 802.11g laptop client - approximately 200 mW output power
3. A first generation 2x2 MIMO 802.11n client - approximately 30 mW output power. Current .11n clients should have even better performance.
4. First generation iPhone smartphone WiFi client.

Let’s first examine the average performance of these clients across all the networks in which they were tested.

Client	Delay (msec)	Uplink (kbps)	Downlink (kbps)	Availability
Average Laptop	157	481	1030	64%
Average High Power	113	767	1286	85%
Average .11n	115	845	1712	82%
Average iPhone	422	231	810	45%

The clear performance advantage of the higher power client and for the 802.11n clients leaps out. Both deliver average megabit performance with approximately 85% outdoor availability - availability comparable to both the best of cellular and pre-WiMax with superior performance. The lower performance of both the standard laptop client and the iPhone client is understandable with the low power iPhone still showing a rather amazing 45% availability on average. The difference a good infrastructure network makes is clear when we look at the best performance by each of these clients. Our top three performing networks (Minneapolis, Toronto, and St. Cloud) all deliver outstanding performance but the single best performances were by the laptop, high power AND .11n clients in Minneapolis - delivering multimegabit performances that leave both cellular and pre-WiMax in the dust - while delivering avaiailability uniforming over 80% - including 100% for the high power client. The St. Cloud network delivered the best performance and availability combination for the iPhone client with 75%.

Client	Delay (msec)	Uplink (kbps)	Downlink (kbps)	Availability
Best Laptop (Minneapolis)	74	457	3090	80%
Best High Power (Minneapolis)	63	2062	2949	100%
Best .11n (Minneapolis)	77	1939	3237	82%
Best iPhone (St. Cloud)	415	158	831	75%

Some conclusions:

1. A modern WiFi network designed with appropriate access node density ( greater than 40 nodes/mi^2) can deliver performance and coverage that outperforms cellular and pre-WiMax.
2. The increasing usage of 802.11n in client devices will only improve the quality of already installed networks ... increasing performance, coverage and user satisfifaction.
3. All the WiFi network infrastructure we tested was 802.11g compatible, often without diversity antennas for the uplink from clients. As infrastructure vendors move from .11g to MIMO .11n we can only expect these performance gains to increase even more.

This is a new entry that I created in MarsEdit. What about tags?

Our web site is sporting a new look and feel thanks to Movable Type and the Professional Template Set. The Professional Template Set makes it possible for just about anyone to get up and running with a new web site using Movable Type. It is literally as easy as just a few clicks. Just pick a new for your web site, select the Professional Template Set and publish. Then viola! a new web site. Thank you Movable Type!

We have been curious about how real wireless networks perform - both in the enterprise and in metropolitan areas. We have also been impressed by how few third party measurements at scale have been performaned for both applications of wireless networks. Most of our knowledge about how these networks really deliver service is either based on anecdotal reports or the marketing information from the service providers and equipment vendors. So we decided to test and obtain some real, non-partial information. We went out and tested over 136 wireless networks in 22 North American cities from July 2006 through early 2008. We devised an network independent testing regime that mimics the behaviour that ordinary users of these services would observe - testing packet delay, upload and download throughput (using industry standard tools) and percentage of the claimed service area in which we could actually get service. We tested in the following cities (some twice to reflect major changes in the networks between tests): Anaheim CA (2x), Brookline MA, Chico CA, Cuperino CA, Daytona FL, Eugene OR, Foster City CA, Galt CA, Longmont CO, Madison WI, Minneapolis MN, Mountain View CA (2x), Palo Alto CA, Philadelphia PA (2x), Portland OR (2x), Raleigh NC, Rochelle IL, St. Cloud FL, Santa Clara CA, Sunnyvale CA, Tempe AZ, and Toronto ON (2x). Where we could find them, we tested cellular data networks from ATT (nee’ Cingular), Sprint and Verizon; pre-WiMax networks from ClearWire and WiFi networks from a variety of ISPs. The data clearly shows that all these technologies can deliver similar levels of service when properly built out. Subsequent blogs will address individual lessons learned for each of these network technologies.

This blog is the combined thoughts of Ken Biba and Phil Belanger ... two pioneers of wireless networking and arguably two of the co-inventors of the networking systems we think of as WiFi:

1. Minimal licensing.
2. Sharing of scarce radio spectrum.
3. Robust technologies that survive (and often prosper) in a severe radio environment.
4. Dirt cheap.
5. Ubiquitous.
6. High performance.

Look for us to be posting product critiques, technology thoughts and the results from our ongoing measurements of both enterprise and municipal networks. Over the last 18 months, we have done extensive studies of many of the foundation myths of deploying large scale wireless networks in both large enterprise and metropolitan environments. We will be reporting on those studies here and many of the implications of those studies on future use of unlicensed technology for providing mission critical network services. The Novarum Wireless Broadband Review surveyed and measured over 100 deployed municipal WiFi, cellular and pre-standard WiMax networks and comprises the largest available database of experience about these networks. We will be using this large experience base to inform our comments ... rather than mere opinion. We look forward to your comments.