Atheros 108Mbs Super G


Tim Higgins has a comprehensive Networld + Interop: Vegas 2003 Report and new product highlights. Among the bigger announcements was Wi-Fi Protected Access (WPA) support from Atheros, Intersil, Broadcom, Intel, Cisco, and Symbol. The final IEEE spec (802.11i), will be called WPA2 when it finally hits the market late this year/ early next.

WPA2 will keep WPA’s authentication and encryption key management features and add stronger AES-based encryption. Tim warns the upgrade path to WPA2 will be limited to products based on wireless chipsets with built-in encryption engines. Most likely, only 802.11b/g and a/b/g products will be WPA2 compatable for upgrades.

Increased speed for Wi-Fi chips was another major development.

Wi-Fi chipmaker Atheros announced jackpot performance at the Las Vegas, Networld+Interop Conference on Wednesday. Their new Super G and Super A/G chips are rated at 108Mbps, using real-time hardware data compression, standards-compliant bursting, and dynamic transmit and modulation optimizations.

Atheros claims to deliver 90 Mbps TCP/IP throughput in 802.11a/g and 802.11g Wireless LANs using its chips while maintaining backward compatibility. How do they do it? 802.11 Planet has the story.

The new 108Mbps data rate design upgrades the original Atheros Turbo Mode and is based on applying innovations from the 802.11g draft standard to enable the higher speeds while maintaining backwards compatibility. It enables data rates up to 108Mbps for 802.11g and 802.11a with full backward compatibility and interoperability with conventional 802.11a, 802.11b or 802.11g (Draft 8.1) products.

It allows the same access point, gateway or client card to simultaneously support 108Mbps 802.11a/g, 54Mbps 802.11a/g, and 11Mbps 802.11b communications. Super G and Super A/G make Wi-Fi easier by allowing users to use networks from 11 Mbps to 108 Mbps without configuring their equipment for a particular type of wireless technology.

Real-time Data Compression is part of the deal.

An Adaptive Hardware Compression Engine is embedded in all current Atheros chipsets. The hardware analyzes network traffic and compresses it in real time using the reliable, standards-based algorithms employed by popular data compression software. With mixed network traffic, the Hardware Compression Engine provides 10 to 30 percent additional throughput.

Standards-Compliant Bursting Capability gives it a boost.

The Atheros “Super” chips enable a standards-compliant bursting capability. It adjusts data frame, acknowledgement and response parameters according to the number of users, level of wireless activity, and other network conditions.

Dynamic Transmit and Modulation Optimizations burn a hole.

Based on measurements of the RF environment, the designs dynamically optimize transmit timings and adjust modulation parameters to improve 802.11a/g communications. Atheros says it increases the multipath resistance while enabling the use of higher modulation and coding rates – and effective throughput.

Atheros claims the Super G and Super A/G designs deliver over 90Mbps TCP/IP throughput for network traffic consisting of compressible data. With less compressible traffic, throughput may be reduced to 70Mbps. Products featuring Super G and Super A/G capabilities operate transparently to the end user and are compatible with all Wi-Fi CERTIFIED products.

The Atheros AR5001G (802.11b/g) chipset and the AR5001X+ (802.11a/b/g) chipset are in volume production and available in products today from OEMs. Atheros-based products are Wi-Fi CERTIFIED, and support the latest 802.11g Draft (8.1 standards). The new Super G and Super A/G performance enhancements are activated through driver upgrades available to Atheros customers this quarter.

Atheros chipsets are used by Proxim’s ORiNOCO Gold and Silver ComboCards, SYMBOL multimode access points, Netgear, D-Link and others.

Atheros competitor Intersil, also announced a software upgrade called Nitro for its own single mode PRISM GT and the dual-mode 802.11a/g PRISM Duette. It uses a burst mode to push speeds to 30Mbps in real-world use.

The IEEE 802.11n Working Group may get in the act. They’re expected to standardize on faster Wi-Fi – from 108 Mbps to as much as 320Mbps – by using new modulation schemes.

Long Haul 54G


Tim Higgins reports the AirStation 54Mbps Wireless card with Antenna Interface ($119), delivers 54 Mbps on the 2.4GHz band. It works with any Type II or Type III CardBus ready PC notebook and the MMX connector extends wireless range and performance with an external antenna.

The G54 AirStation PCI Card comes with an Omni Antenna ($139), an MMX antenna jack and is bundled with a 2.2dBI omnidirectional antenna.

Buffalo Tech’s WLA-G54 AirStation ($189) is a 54Mbps Bridge Base Station featuring a Wireless Distribution System (WDS) Bridge/Repeater with integrated 4 port 10/100 switch that supports point-to-point and point-to-multipoint bridging and wireless repeating.

Broadcom-based, 54-G product outputs 32mWatts. You might plug in a +14dB panel ($37), a +18dB panel ($69), a +19dB panel ($49), or a +24dB grid antenna ($149) and see how far you could go.

A directional antenna, in the 2400-2483.5 MHz band used exclusively for fixed, point-to-point operations, “may employ transmitting antennas with directional gain greater than 6 dBi provided the maximum peak output power of the intentional radiator is reduced by 1 dB for every 3 dB that the directional gain of the antenna exceeds 6 dBi”.

FCC Power Regulations from the Telex FAQ on 2.4 GHz

Q: How much power can I transmit on a 10 dBi omni at 2.4GHz and still be legal?

A: The FCC regulations for PtMP allows only 36 dBm (4 watts) EIRP. This is 30 dBm (1 watt) into a 6 dBi antenna. If you use a 10 dBi antenna, you must limit your transmitter (or amplifier) to 26 dBm (10 + 26 = 36 dBm). A 200 mW card (+23 dB) can drive a (+13dB) panel (+36dB total). If you figure a – 1.5dB cable/connector loss, you could legally drive a 14.5 dB panel. Power is measured at the antenna connector, so subtract any cable loss between the amplifier and the antenna. Refer to the following table:


Power at antenna (dBm/Watts) Antenna Gain (dBi) EIRP (dBm) EIRP (watts)

30 dBm (1 W)

6

36

4

27 dBm (500 mW)

9

36

4

24 dBm (250 mW)

12

36

4

21 dBm (125 mW)

15

36

4

18 dBm (62 mW)

18

36

4

15 dBm (31 mW)

21

36

4

12 dBm (15 mW)

24

36

4

A 2.4 GHz omni antenna is restricted to 4 watts EIRP. But, if you knock off -3db loss for cabling and a lightning protector, you’d still be FCC street legal using Broadcom’s 32mW (+15dB), feeding a +24dB dish (+39dB – 3dB loss = 36dB). You could put one on a roof or nearby hill, for example, and hit dozens of clients along a linear street or park.

Point-to-point links can use lots more power. A Subscriber Unit that only talks with a central AP is considered to be PtP and can use more power. A client using a 200mW (+23db) card can legally use a +23dB antenna. The FCC allows significant “passive” gain in client antennas.

Q: How much power can I transmit with in my 2.4 GHz Point-to-Point system?

A: According to FCC regulations, 2.4 GHz Part 15.247 point-to-point transmitters may use a 30 dBm transmitter with a 6 dBi antenna. For a 3 dB increase in antenna gain, the transmitter power output must be reduced by 1 dB. Power is measured at the antenna connector, so subtract any cable loss between the amplifier and the antenna. Refer to the following table:


Power at antenna (dBm/watts) Max Antenna Gain (dBi) EIRP (dBm) EIRP (watts)

30 dBm (1 W)

6

36

4

29

9

38

6.3

28

12

40

10

27 dBm (500 mW)

15

42

16

26

18

44

25

25

21

46

39.8

24 dBm (250 mW)

24

48

63

23

27

50

100

22

30

52

158

A stock 200 mW PC card (+23dB) can feed a +24dB dish (in point to point mode) and still be street legal because you can go up to 63 watts (+48dB). A solid-state Soekris box with a couple of 200 mW cards feeding a couple of 24dB dishes, is, in fact, the basis of the Bay Area Wireless Metro Network. Each relay node costs about $2,000.

Things get dicey if you add an amplifer. YDI’s +18dB antenna has a built-in +14dB amplifier ($495). That raises a 32mW (+15dB) radio like Broadcom’s 54G to a total of +29 dB output power. Then add the passive +18dB antenna gain and you get a total gain of (29dB + 18dB) or +47dB gain. That’s over the FCC limit.

But not by much. Because we are using a high gain antenna, we can use more power. We are only required to knock off -4 dB (if my calculations are correct). So instead of 1 watt feeding an +18db antenna we must limit ourselves to about 400 mWatts feeding the antenna.

That’s not bad. YDI’s +14dB amplifer boosts the 32mW (+15dB) radio to about 800mW (+3dB too much). But cabling and a lightning protector will knock off about -3dB so we might be right on the FCC-legal limits. We might use the YDI amplified antenna without power reduction (in long haul, point to point networks). Stock. 54G.

How far can you go?

Calculating Wireless Range:
How far can YOU go? Young Designs has an online calculator for determining range. Michael Young recommends a minimum of +10 dB to +20 dB “fade margin”. Compute your System Operating Margin (fade margin) using his on-line calculator. For sensitivity start at -88dB for a 2.4 GHz radio (at 1 Mbps). For faster speeds, use a -70-80 dB sensitivity for starters.

Roughly speaking, you combine the losses (path loss, cable & connector loss) with the gains from the antennas, radio output and sensitivity of receiver. Using (dB) instead of milliwatts (mW) simplifies calculation because you can just add and subtract the numbers.

Power needs to be translated from millwatts (mW) to decibels (dB) in order to use the calculator. Here’s the dB translation you can substitute in the on-line calculators; 30 dBm (1 W), 27 dBm (500 mW) 24 dBm (250 mW), 23 dBm (200 mW), 21 dBm (125 mW), 20 dBm (100 mW), 17 dBm (50 mW) and 15 dBm (30 mW).

So figure this; add 15dBm (30mW) for a Broadcom radio and +14dB for the antenna amp. That totals +29dB. Then add +18dB for the antenna (take out -3dB for losses). Sensitivity goes down sharply with higher speed and 54Mbps is a real killer. Let’s estimate a radio sensitivy of about -80dB (at 12Mbps) as a compromise.

Other on-line calculators include the Cable loss Calculator, Wireless Link Calculator, Distance Calculator, Fresnel Zone Calculator, Beam width Calculator, as well as other free community networking software. Antenna suppliers include Hyper Link, Super Pass, Telex and YDI.

Plug in your own numbers. Long-range, point-to-point in the 2.4 GHz band probably shouldn’t be using stock Wi-Fi components due to the constraints of the protocol (it’s designed for local area networks, after all).

The 5 GHz band & the 802.16a

The 802.16 Wireless LAN standard provides a communications path between a subscriber’s site and the Internet or ISP. The 802.16 standard (summary), supports a Metropolitan Area Network (MAN), not a Local Area Network (LAN). It assumes a point-to-multipoint topology with a controlling base station that connects subscriber stations not to each other but to various public networks linked to the base station. It is a connection-oriented service with full Quality of Service.

According to FCC Part 15.407, 5.8 GHz UNII-3 wideband digital fixed point-to-point transmitters may use a 30 dBm (1 watt) radio with directional antennas with up to 23 dBi gain without ANY corresponding reduction in transmitter power. Maximum EIRP is 53dBm (200 watts).

Power at antenna (dBm) Antenna Gain (dBi) EIRP (dBm) EIRP (watts)

30

6

36

4

30

9

39

8

30

12

42

16

30

15

45

31

30

18

48

62

30

21

51

125

30

23

53

200

29

24

53

200

28

25

53

200

It’s not hard to imagine someone offering a 5.8 GHz amplified antenna for the 5.8 GHz Atheros card. Atheros puts out about 40mW (+17dB) at 5.8 GHz. An amplified 5.8Ghz antenna might boost it another +13dB and the antenna gain for a panel might add another +23db.

That’s +53dB total. The FCC legal limit. Then add QOS. With 1 watt radio and a +23dB panel, you should get about 15 miles at 12Mbps (with a +16dB fade margin).

Perhaps 5 GHz, 802.16a backhauls could feed three-sector, 802.11g neighborhood nodes or Vivato (3-mile) scanning beams on rooftops.

Ring around your city. Welcome to the neighborhood. You’re on the net.

Proxim Net Manager


The improved version of Proxim’s Wireless Network Manager is available as a free upgrade for existing users. The Wireless Network Manager is available in a variety of options depending on network size and configuration, starting at MSRP $999 (Base Engine + 50 AP Device Module. A free evaluation version, good for 30 days, is available on the Proxim web site.

The Wireless Network Manager can control, update and configure Proxim wireless networks via a single Graphical User Interface (GUI). Operating either as a standalone program or a HP OpenView plug-in, the new version 1.4 of the Proxim Wireless Network Manager enables an IT or network manager to easily monitor, manage and upgrade an entire indoor or outdoor wireless network from a single location.

Proxim AP-600, AP-2000 and AP-2500 access points for 802.11a and 802.11b networks are supported. Thousands of enterprise class access points, outdoor point-to-point and point-to-multipoint access points and bridges, as well as small business access points located in remote and home offices, can be managed over an IP connection.

Last Mile Technologies has deployed Proxim gear in a city-wide wireless network in Mount Pleasant, Michigan. Eight apartment complexes, which house 4,500 students, are currently using the wireless network, and additional apartment complexes housing another 5,000 students are slated for completion by August 2003.

Proxim’s Tsunami Point-to-Point and Point-to-Multipoint outdoor wireless products provide wireless backhaul throughout the city. Within buildings and at public access hot spots, users can connect to the wireless network using Proxim’s ORiNOCO 802.11a and 802.11b indoor APs.

E-mail Talker


Scorpio Software has released E-mail Talker 2.7, MSN Hotmail and POP3 email talker for Windows.

E-mail Talker 2.7 is email notification software for Hotmail, POP3 accounts. Speaking animated character reads aloud incoming emails. Features antispam filtering, simultaneous account checking. Lets you listen to your emails, web pages, documents, help files or anything else you copy to the clipboard. E-mail Talker Online Manual (HTML help) contains Character Gallery with 30 characters.

Geocoding the Wiki


Jerritt Collord has added a new dimension to the collaborative Wiki conceptGeoWiki. It allows anyone to Geocode Web Pages. Jerritt explains how it works:

In GIS-speak, it will provide a way to collaboratively manage place names and descriptions and provide geography specific information services.

Ultimately it will play a role in the juxtaposition of information services and geographic location.

In terms of Wiki it will extend “accidental linking” into the geographic realm.

To use GeoWiki on this wiki, use once in a wiki page (except enclosed in “[[“) the macro function like GeoWiki(‘address’,’2052.SE.Morrison.St.Portland.OR.97214′) or GeoWiki(‘point’,’-122.4323′,’46.4553′).

This registers this wiki node with the database. Then, you can call GeoWiki(‘near’,’1000′,’meters’) and get back a list of other nearby wiki nodes and PTP nodes.

To map a wiki location, call [[MoinMap(‘wiki’,’MyWikiPage’)]]. See also MoinMap

How do you get your coordinates? Go to Geocode and type in your address. Your latitude and longitude will come up.

Why not “map” the people in your neighborhood?

Retrieving any memory from one’s life is becoming practical. Mapping areas of interest around each neighborhood is halfway done. With neighborhood involvement, residents could get hands-on while creating a resource for the whole community. Gordon Bell’s project, MyLifeBits, scans his books and family photos. Cityblogs and Blockblogs – created at no cost – could establish long-term resource hubs. Content run by and for local people, could link to the larger community. Local news and features could be syndicated by topic and location and feature sections for classified ads and birthdays that month.

City Repair’s T-Horse (above) demonstrates how a space can be transformed into a place. Unwired.

Oral histories could be recorded and Geo Coded via Lat/Long in URLs or Blog Mapper, then available in the “blogosphere” from any web browser or on a CD/DVD. Portland Maps (or anyone) could use it.

Geocoding is the key. Related Daily Wireless stories include Narrative Geocoding, Transit Mapping, Neighborhood Netcams, Tracking Bryon, Unwalled Garden,l Talking Books and Tri-Mode community LANs.

But the real is often not the ideal.

Wendy Mackay documents Xerox EuroPARC’s now-defunct experiments with embedded social software, in which easily-available multimedia connections were spread through both the public and private areas of the workspace.

The goal was to foster casual workplace social connections by creating a sense of shared presence and making audio-visual communication easy. However, while they may have intended to break down existing social barriers, the system continued to reflect the real-world social roles and hierarchies of the group.

Free Wi-Fi Illuminates New York


On Friday, May 1, New York City’s Downtown Alliance is expected to launch three public Wi-Fi network nodes to give away high-speed wireless Internet access and four more will go live later in May.

New York’s City Hall Park, Bowling Green Park, and Rector Park will be activated later this week. Later this month, nodes will be available in Liberty Plaza Park, Vietnam Veteran’s Memorial Part at 55 Water Street and at South Street Seaport.

Vivato is reportedly working with members of NYCWireless to provide a cloud of Wi-Fi connectivity over Central Park. Vivato estimates about four of their outdoor phased array units will cover the entire 843-acre park.

The ‘hotspots’ being turned on this May are built and maintained by wireless networks consulting firm Emenity, which is a spin-off of the non-profit NYC Wireless, a pioneer of open wireless ‘hotspots’ in public spaces throughout the New York region. Emenity, also built a Wi-Fi ‘hotspot’ in Bryant Park on 42nd Street.

Emenity spokesman Anthony Townsend told internetnews.com the rollout of the ‘hotspots’ downtown would create a Wi-Fi enabled zone “anywhere within a five-minute walk in Lower Manhattan.

The Downtown Alliance, is spending about $50,000 to set up the ‘hotspots’ and less than $20,000 a year to keep them running. “They (Emenity) gave us a fantastic deal on this and the benefits are huge for our district. First of all, it’s going to be a wonderful area amenity for downtown residents, workers and visitors,” said Jordan Silbert, Director of Rebuilding Initiatives for the Downtown Alliance.

For Emenity, the Downtown Alliance deal adds a big-name client to its roster for wireless network consulting services. The six-employee firm is avoiding the subscription-based Wi-Fi services — adopted by Starbucks and cafes nationwide — in favor of free public networks that “differentiate real estate space,” Townsend explained.

To install, run and manage a Wi-Fi ‘hotspot’ (a single access point and including bandwidth), Emenity charges less than $20,000 a year, Townsend said, noting that the company was looking at a wider variety of spaces beyond the coffee shops and hotel lobbies.

The Downtown Alliance’s claims it’s the “largest free wireless zone” in the country. On the West Coast, SeattleWireless, Portland’s PersonalTelco and the Bay Area Wireless Users Group have also been promoting free Wi-Fi hot spots for the public. Portland was recently named “the most unwired city” in the nation.

According to the Urban Research Initiative;

“The economic future of our cities will be defined by their capacity to generate, process, and distribute information”. With the emergence of the Internet, the diffusion of personal computers and the advent of telecommunications deregulation, cities face unprecedented requirements to compete as centers of economic activity, culture, and civic activity”.

Here’s a plan to build the unwalled garden. The city of noses.