Category: Hardware

January 15, 2008

Apple Adds iPhone Location over Wi-Fi, Base Station Backup, MacBook Air

By Glenn Fleishman

Apple plays to my interests this morning with a set of new products and upgrades tied into wireless data: The news out of San Francisco—where I’m on site—is that Apple is rather keen on Wi-Fi. The company announced several upgrades and new products that take advantage of a lack of wires.

The iPhone location update: The iPhone can now figure out your location by triangulating either the location of nearby cell towers or by fishing around for WI-Fi signals. The cell-tower system uses information from Google, which also provides the map data. Wi-Fi location details come from Skyhook Wireless, a firm I’ve tracked for years. Because the iPhone can make a connection over either EDGE or Wi-Fi, Skyhook confirmed for me that the iPhone can take its snapshot of the signals around it and transmit that to their servers over either Wi-Fi or EDGE. When connected to a Wi-Fi network, the query can go over Wi-Fi, of course, but could be coupled for better results with cell radio sniffing, too. The iPod touch also gets this Maps improvement, along with a handful of other additions, as a $20 upgrade for existing users; it has to be connected to a Wi-Fi network with Internet access to provide a location, however.

Time Capsule: Apple has scored the much coveted double-win on backups here, by coupling an operating system based backup feature (Time Machine) with a network-attached storage system that requires no configuration. Time Capsule incorporates a full AirPort Extreme Base Station (with 802.11n) with an internal 500 GB or 1 TB hard drive for $299 or $499, respectively. The base station is $179 when purchased by itself. A home network could have one of these puppies and accomplish several related tasks. Backup is for Mac OS X 10.5 (Leopard) only, which is a shame, but Apple would like people to upgrade to Leopard ($129) or buy new computers, so one can’t precisely blame them.

MacBook Air: The “Air” refers to the lack of connections on this starting-at-$1,799 3 lb, high-performance laptop with a 13.3-inch screen, 80 GB drive, and 2 GB RAM. The MacBook Air has very few connections: there’s a USB port, along with a mini-DVI connector and headphone jack, hidden behind a latch, but there’s no FireWire (IEEE 1394), no optical drive, and no Ethernet jack. A external optical drive is $99 or you can use another drive on the network (Windows or Mac) via some special software that mounts the drive without any networking hassles. It includes 802.11n and Bluetooth 2.1+EDR.

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January 3, 2008

San Francisco Gets Free Wi-Fi, Courtesy of Meraki

By Glenn Fleishman

Meraki Networks raises $20m in additional funds, spends a small portion on providing free Wi-Fi across San Francisco: Meraki, founded by MIT students, funded by Google, Sequoia Capital, and others, will expand its current 2 sq mi mesh Wi-Fi network in San Francisco across the whole city. Meraki will foot the backhaul bill and pay for equipment—but it won’t pay for real estate. The city will help publicize the network, but I haven’t read anything concrete about the city’s plans. (Read good local coverage in the San Francisco Chronicle.)

The clever bit here, and how Meraki may succeed where EarthLink failed, is that the firm is relying on individuals and businesses to choose to opt in, site equipment, and take advantage of the network working better for everyone because they participate (paging Ayn Rand). Meraki plans to offer solar-powered outdoor nodes for extending the network’s reach, which means potential locations don’t have to provide electricity on rooftops or elsewhere, which in turn means fewer or no layers of approval from anyone in authority (whether a neighborhood association, landlord, or the city). “It’s relatively easy to install on private rooftops,” said Meraki CEO and co-founder Sanjit Biswas in a briefing earlier today.

In the process, Meraki gets a city-wide testbed for local search, local ads, and new technology. “The great thing about having a real-world testbed is you can see the performance,” Biswas said. Meraki is testing advertising now, but Biswas says it’s “very much in the test mode.”

While Biswas didn’t disclose any of the costs of building the city-wide San Francisco network or its recurring bandwidth bill for backhaul—he told the AP “a few million”—the math works for Meraki. Giving away 10,000 to 15,000 nodes that cost them as little as $25 assembled for  indoor nodes and a few hundred for outdoor nodes with solar  chargers and batteries doesn’t add up to a lot. They don’t have to negotiate pole rates, handle installation, or pay recurring venue fees. Bandwidth is relatively cheap if you can choose the points at which you inject it, which Meraki will be able to do. Update: I misunderstood the backbone part. Meraki will, in fact, install some hundreds of solar-powered outdoor nodes to run the backhaul; but they’ll still be working with people to find those locations rather than securing those rooftops themselves.

Meraki has learned quite a lot about the real world, Biswas said, with their current San Francisco network, having identified 20,000 interferers—other devices within range and frequency of Meraki nodes—within the 2 sq mi area. Meraki nodes use a centralized intelligence to control routing, as well as a modification to Wi-Fi that doesn’t affect end users’ ability to connect, but does allow clusters of routers to act dynamically as a unit.

With unmodified mesh Wi-Fi networks, all devices within range of one another and on the same channel act in concert, reducing flexibility and throughput; smaller clusters produce better results. Further, most of the metro-scale Wi-Fi devices sold by Tropos and others are designed to put out the highest possible power output; Meraki uses generally low-power equipment. It’s ants versus elephants, with ants being able to change course a bit more quickly. “It’s kind of a brains over brawns approach. It’s really because we have so many radios,” said Biswas, that their network is more flexible. “We can set routes and load balance appropriately to get the maximum performance out of the network,” Biswas said.

The current San Francisco network has seen 40,000 unique devices so far—there’s no registration, so each unique adapter number is counted—and moved over 10 terabytes of data. Of those 40,000 devices, 1,000 were iPhones.

Biswas said that Meraki has discovered its biggest market may be developing countries where there’s an established user base for the Internet that’s limited to dial up or slow-speed broadband, and where carriers could deploy Meraki gear to get around non-existent copper infrastructure.

“A lot of our largest customers are carriers that are entering markets in Brazil and India,” he said. “We’re not at this point going after the most remote villages in the world; there are some very dense populations who…would love to use broadband but just can’t get it.”

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November 1, 2007

Pepwave Drops Price of Bridge for Muni Networks to $99, $129

By Glenn Fleishman

The company decided to take some of the pain out of municipal deployments by extending its bulk price to individuals on its entry-level Wi-Fi bridge: In metro-scale networks, it’s become clear that to get good indoor reception in most cases, you need a bridge. The popular bridges from Pepwave and Ruckus Wireless pick up a faint signal from a city-wide network and then essentially rebroadcast it under a different network name for users in proximity. These bridges used to start at about $150 for units with 200 milliwatt (mW) radios, which is from twice to septuple the power of built-in adapters; they usually put out 30 mW to 100 mW of juice.

The price has fallen, though, and while $100 isn’t free, it’s approaching a level that I suspect more people are comfortable spending to improve access in areas with coverage. Ruckus Wireless’s MetroFlex DZ has a list of $149, but ExpressNets will sell it to you for $99; and Pepwave’s comparable Surf AP 200 can now be bought for $129. The Surf 200, which lacks the second home network feature, is $99.

Pepwave has dropped its 400 mW Surf AP 400 from $289 to $189, which could be useful, too, in the right circumstances, but receive sensitivity is a more critical measure than transmit power in trying to “hear” distant signals. The AP 400 has a small but measurable improvement in receive sensitivity over the two 200 models. I can’t find Ruckus’s receive sensitivity numbers readily, but their approach involves multiple antennas, in which beam forming and multi-path reflection analysis provide their own improvements in range and reception.

Update: Ruckus provided their receive sensitivity numbers, which in nearly all cases exceed the Pepwave AP 400’s numbers for nearly $100 less. Now, this requires real-world testing to see whether the multiple antennas and this higher measured sensitivity equate to a greater service area, but the raw numbers are good.

Update: Pepwave notes that in its testing transmit power is more critical; their perspective is that with metro-scale networks, the nodes can push power out quite well - often using the legal maximum - but it’s difficult for them to hear distant, faint clients. An iPhone, for instance, can hear a far-distant transmitter, but can only call back weakly.

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October 31, 2007

Bluetooth to Add Wi-Fi with UWB Delays in Mind

By Glenn Fleishman

The Bluetooth SIG will create a version that runs over Wi-Fi: Bluetooth comprises applications and radio standards. The applications include standard profiles that developers use to add features like keyboard and input device access, file transfer, and dial-up networking. The Bluetooth SIG has a long-range plan to keep Bluetooth relevant by essentially adding more radio technologies underneath, not just the 1 Mbps version found in Bluetooth 1.x and the 3 Mbps version in the Enhanced Data Rate (EDR) part of 2.x+EDR.

Ultrawideband (UWB) was one of the preferred newer radio standards, something they decided on supporting in March 2006, because UWB seemed to be near term at that point, and was part of the original migration path for personal area networking in the IEEE 802.16 group that Bluetooth has some coordination with. (UWB was to be the radio standard for 802.16.3a until the group disbanded over friction caused by a now-dropped original flavor of UWB from what is now Motorola spin-off Freescale.) UWB is low-power and low-range, making it ideal.

But it’s hardly on the market yet and is way too expensive. This pushes back Bluetooth over UWB in handsets to something like 2009. TechWorld notes that UWB vendors say that UWB handsets will be on the market (in Asia) within six months. Of course, UWB chipmakers and manufacturers have been telling me since 2006 that UWB products will be shipping in a few months. They weren’t lying; complications ensued. I accept that. But I’m now Missouri as regards UWB in shipping hardware.

As a result, TechWorld reports, the SIG’s chair, ironically a Motorola employee, said that they would focus on building Bluetooth over Wi-Fi. Details aren’t available, and one UWB vendor says that Wi-Fi and Bluetooth are incompatible due to security models.

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October 23, 2007

Linksys Draft N Router Offers Two Bands at Same Time Along with Many Tradeoffs

By Glenn Fleishman

The Linksys WRT600N sets out to offer what no router to date can (updates added 31 Oct 2007): certified Draft N networking simultaneously in the 2.4 GHz and 5 GHz bands: This is a neat feat, but requires two radios to carry out, and carries with it a hefty $280 price tag. In testing, I found a number of design choices and missing features, along with a lapse in the standards certification process, that make me suggest that users wait for firmware updates before purchasing an otherwise quite capable router.

The WRT600N’s closest competitor is the Buffalo Wireless-N Nfiniti Dual Band with gigabit Ethernet released in March for $250; it’s not yet Draft N certified by the Wi-Fi Alliance, hence the Linksys unit’s current uniqueness. (Read SmallNetBuilder’s review.) Update, 31 Oct 2007: Buffalo is currently enjoined from importing its 802.11a, b, and n gear into the U.S.

The idea of offering both bands in a single router is simplicity: You can throw away old gear while preserving backwards compatibility and not sacrificing range nor throughput. Devices that can use the 5 GHz band and that you want to have running at full throttle can do so, particularly important for video streaming. This also allows you to reduce clutter, and to migrate older equipment to newer adapters as (or if) they’re available instead of all at once.

The Ultra RangePlus Dual-Band Wireless-N Gigabit Router (WRT600N)—to use its unwieldy full name—uses Linksys’s EasyLink Advisor, a piece of wizard software the company has been rolling out gradually across all its models. (It can be downloaded and used with certain older devices, too.) While the EasyLink Advisor does streamline setting up a new router, troubleshooting problems, and passing out a wireless security key, it was also maddeningly slow in “discovering” the router it was trying to reach, to which it was directly connected via Ethernet on a modern, fast Dell laptop running Vista. I found it unable to configure an internal Intel Wi-Fi adapter to connect to the network, despite its assurance that it could do so.

The router also offers the usual ancient Linksys interface behind the scenes via a Web browser for advanced configuration. I found for my basic purposes, the advisor didn’t offer enough, and I expect that any user who finds the need for a dual-band, simultaneous 2.4/5 GHz router will also find the advisor inadequate because of specific settings they’ll want to make “by hand.”

The WRT600N has four 10/100/1000 Mbps Ethernet ports. The case is a sleek black, with LEDs on the front that display the status of ports, the Internet connection, and Wi-Fi security (enabled or not). It has a single USB port to accept a hard drive or flash drive.

The WRT600N succeeded in its primary goal in life: Providing access to two separate networks while shunting data over gigabit Ethernet to directly connected devices. The 2.4 and 5 GHz networks can be set with unique names and have separate security options.

In testing for throughput, I found that the WRT600N was highly inconsistent, but that’s clearly due to my particular RF environment. Although my office is a mixed retail/office/residential building, and the neighborhood isn’t that dense, we have some problem on channel 1 in 2.4 GHz that renders networks in that range completely unusable, regardless of vendor. A spectrum analyzer hasn’t disclosed the cause.

In 5 GHz, I see some strangeness at times, too. As a result, I can’t benchmark devices with confidence when I see low or erratic numbers that don’t hold up to repeated tests. Conversely, when I see consistent high performance in such a difficult environment, I can rely on the robustness of the device.

In general, I was able to see speeds across 2.4 GHz and 5 GHz that should be expected from Draft N devices, but I’m declining to note them due to my test environment. Tim Higgins of SmallNetBuilder will have extensive, controlled test results in a few days which I’ll link to. Update: These benchmarks are now available in Higgins’s extensive review. I see that the number I saw aren’t that far off from his more controlled tests.

Now on to some specific concerns.

Security. If you use the EasyLink Advisor, as Linksys expects many of its users will, you cannot choose your security key; the advisor creates a strong alphabetic-only key for you. That’s great, but if you don’t want to use the methods available for distributing that key to other computers, you have to type in a rather long set of characters.

The advisor can create an installation program with the key embedded that can be copied by the advisor onto a USB drive or transferred over a local network by connecting an Ethernet cable to a LAN Ethernet port. I tested the USB drive method, which exported fine but failed to install on a Windows XP SP2 system without enough explanation to troubleshoot the problem. (That system had the Linksys WPC600N dual-band card installed—the $100 one-band-at-a-time counterpart to the router—and all drivers were up to date.)

I would have liked to use Wi-Fi Protected Setup (WPS), as I now have a few computers that should be able to work with it. Unfortunately, in what appears to be a late decision in the release cycle, the WRT600N lacks WPS. There’s a button on the top of the router that has a plastic laminated sticker around it labeled Reserved. I confirmed with Linksys that this release lacks WPS. It’s a shame.

I wound up using the advanced configuration to set my own WPA2 passphrase—which can be set uniquely for each radio—to make it easier to add computers. That worked perfectly.

DHCP assistance. I like the DHCP Reservation system, which may not be unique to this model, but it’s new to me. DHCP reservation lets you pick an IP address that remains persistent for a given device based on its MAC address, or the name that’s set for the machine, and broadcast as part of the DHCP request. (On Macs, there’s an option called DHCP ID, which is set separately, and can’t be used for Windows machines.)

If you’re trying to find the list of attached clients over DHCP, you use the DHCP Reservation button in the main Setup screen. It shows the client, and how it’s connected: via the wired LAN or a wireless connection, where it shows which band it’s connected via.

Picking SSIDs. Linksys made a strange decision in having their EasyLink Advisor set the same network name or SSID for both the 2.4 and 5 GHz networks. For adapters that support both bands, there’s no simple way to mark which network you’d prefer to join. I found in testing that Linksys’s own WPC600N dual-band PC Card joined the 2.4 GHz network, and I didn’t see a way to change that behavior. I don’t know of any tools in Windows or Mac OS X that let you preferentially set the band for networks that roam across bands, not just routers.

The advisor also won’t let you choose an SSID which contains spaces, which is baffling. Linksys told me that this is due to legacy support issues as the advisor can handle older routers that cannot accept spaces in SSIDs. Sad that the advisor isn’t smart enough to know which routers can and cannot, since spaces improve the legibility of a network name.

Again, I went into the advanced setup and entered separate names for my two networks. That worked perfectly.

Wide channels by default in 2.4 GHz. Linksys has chosen to release a router that’s configured in opposition to the Wi-Fi Alliance certification standards; it’s a loophole. Linksys ships the WRT600N set to use 40 MHz channels in 2.4 GHz by default, which means that when you turn the device on, you will interfere with double the number of networks that you would otherwise. The Wi-Fi Alliance Draft N standards say that the default should be 20 MHz, with manufacturers able to decide whether users can optionally enable wide channels. However, the alliance doesn’t test for this (or even have a checkbox, apparently); Tim Higgins wrote about this last week. Update: Higgins writes on 31 Oct 2007 in his review of the WRT600N that he cannot observe the gateway dropping into 20 MHz channels as it should.

If the WRT600N would follow the standard procedure of not transmitting using a 40 MHz channel when there’s traffic present that it would step on, among other characteristics, that would mitigate this problem. It would essentially moot the issue, as despite being set to 40 MHz, the router would never use a wide channel if the wrong conditions were in place.

There are three mechanisms in the Draft 2.0 version of 802.11n that are supposed to prevent Draft N devices in 2.4 GHz from sending data over wide channels in those routers that will support 2.4 GHz wide channels. I can’t determine whether Linksys has implemented these mechanisms. It remains to be seen whether Linksys is acting as a good neighbor or an indifferent one.

In the best outlook if the WRT600N doesn’t back off to 20 MHz before transmitting, adding a WRT600N is like adding two 2.4 GHz Wi-Fi networks, which happens all the time. In the worst outlook, the default Linksys choice degrades the shared commons far more than it needs to, thus making everyone’s experience in your airspace somewhat worse.

Inadequate 5 GHz channel selection, but commensurate with everyone else. Linksys, like other manufacturers, supports just eight of the 23 possible 20 MHz channels in 5 GHz: the four lowest and the four highest, known as UNII-1 and UNII-3. The middle 15, UNII-2 and UNII-2 extended, aren’t available. Apple made the same call.

A Linksys spokesperson explained that because the middle 15 channels require additional FCC certification, a backlog in that testing has prevented the inclusion of these channels. Devices that use UNII-2 and UNII-2 extended frequencies must detect and avoid radar that’s in use on some of those bands around the U.S. as part of the compromise that opened more spectrum up in 5 GHz. Apple hinted to me in August that something was afoot, too. Some changes went into effect in July for legacy channels (UNII-2) that seems to have slowed certification down.

The Linksys router selects the optimum 5 GHz channel out of the four 40 MHz or eight 20 MHz it supports by default. But if you change the router’s configuration from Auto to choose a specific channel, you are limited to just the lowest four (UNII-1). This is a bit baffling.

Conclusion. A number of choices have led to this router being harder to set up for a user that might demand two bands than it should have been. The lack of WPS makes it more difficult to secure for average users. And Linksys’s specific choice to release a loopholed router under Draft N certification rules is simply baffling.

With firmware upgrades, I expect this router will shine. But I’ll have to wait to see such upgrades before I could warmly recommend it.

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September 12, 2007

Pepwave Enters Mobile Wi-Fi Router Business

By Glenn Fleishman

Pepwave Mobility can keep an active Wi-Fi connection at up to 75 mph, the company says: The device is the first mobile router I’m aware of that’s designed as a separate product, rather than as part of an integrated package that includes propriety elements and often installation and maintenance. They have no per se competitor that I’m aware of for this segment. The company plans to sell the unit to service providers and others starting at $495 for a 100 mW radio (European market), with higher prices for 200 mW and 400 mW radios (U.S.).

Enabling mobile communications in commuter vehicles was supposed to be one of the ancillary benefits of city-wide wireless networks, but it’s been mostly ignored. Most commuter-based Internet access over Wi-Fi uses satellite or cellular backhaul.

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August 21, 2007

Wi-Spy Spectrum Analyzers Shows What's in Your Wireless Backyard

By Glenn Fleishman

To understand what’s wreaking havoc on your wireless networks, a spectrum analyzer is key: Sure, you can make guesses. Talk to neighbors. Use Wi-Fi and Bluetooth scanners. But those approaches have limits. What you really need is a spectrum analyzer that can scan the surrounding area across a frequency range and show numerically and graphically what’s in the air around you. By moving around with a mobile analyzer, you can pinpoint actual problems, and see displayed over time a moving target as to what’s destroying your network’s utility.

MetaGeek has two affordable options for desktop Mac OS X, Windows, and Linux analysis, both of which come in the form of a USB stick. When I say affordable, I mean that their units retail for $199 and $399 versus $2,000 and up for full-featured IT management packages and hardware or standalone devices. The two options scan the 2.4 GHz band used for 802.11b/g and one of the bands 802.11n supports. Bluetooth, ZigBee, and cordless phones—among many other devices—also use the band.

The original Wi-Spy debuted over a year ago; the Wi-Spy 2.4x is a more recent entry from June of this year. The differences between the two units were originally software support, with Mac OS X software available just for the original WiSpy at the launch of the newer device. The Wi-Spy 2.4x now has two Mac OS X supporting applications, too, due in part to the programming interface provided by MetaGeek.

MetaGeek has a nice comparison table that explains the difference between the original and 2.4x versions of their product. It boils down to the 2.4x offering greater resolution—it can capture signal strength on a smaller set of frequencies at once—along with higher sensitivity, and an antenna. The antenna can be removed and replaced with others using the same jack style (RP-SMA).

I tested both units in my office under Windows Vista and Mac OS X. My office in Seattle’s Fremont neighborhood, a mixed retail/office/residential area, has a plethora of Wi-Fi networks. I can see from eight to 14 networks in my office, which is nestled inside a building. I tried turning on a microwave oven adjacent to my office to see what effects that created, too.

Using MetaGeek’s own Chanalyzer software, I could watch Bluetooth dancing all over the 2.4 GHz band. Chanalyzer lets you set mark points to track in planar view, in which activity is marked for average and maximum uses across the band, while a live line shows current signal strength. The topgraphic view shows a concentration of activity over time. The spectral view is a moving track that you can replay and change the time dimension on to expand or contract a moment you’re viewing. The program lets you “record” a scan, which you can replay in the software. MetaGeek also created a community for sharing scans among those interested in that sort of thing, and has samples you can download and replay in Chanalyzer to show various tests they’ve performed. (Chanalyzer 2.1 works under Windows. WiSPY-Tools is an independent Linux, BSD, and Mac OS X package with similar features. MetaGeek has a beta of Chanalyzer for Mac that’s not currently linked on their Web site.)

The scan above shows the normal environment—fairly congested, and you can see the Bluetooth spikes (by clicking to view the full-size image) as lines that leap up in yellow in the planar view. When I turned on the microwave oven, there was some impact (see at left). In the spectral view, you can see the diagonal green lines between 1 and 2 minutes on the time scale when the microwave was first active; I turned it on again briefly and you can see another set of angry lines. In the topographic view, notice the haze of interference rising above the deeper, thicker red band.

I also experimented with EaKiu, a free and independent Mac OS X software package that supports both the original Wi-Spy, and was updated recently to version 4.0 with Wi-Spy 2.4x support. The package offers some interesting 3D options for visualization, in which you can rotate a continually updating series of receding planes.

I honestly found it tricky to figure out how to test the Wi-Spy models since I had no particular issues facing my rather ugly RF environment at the office, but one fortunately dropped into my lap. Apple recently released its revised model of AirPort Extreme Base Station with Draft N by adding gigabit Ethernet. They also tuned some internal firmware issues to improve speed when network address translation (NAT) was in use. For a review in Macworld magazine, I re-ran the same performance tests that I put the Extreme through in February. In the 5 GHz band, everything was copacetic: terrifically improved speeds due to the gigabit Ethernet removing internal limitations that restricted performance.

But in 2.4 GHz, I was stymied. I could hardly get my N adapters (Intel and Apple) to connect to the base station. With Apple’s advice, I turned off Automatic channel selection and chose channel 1. I was seeing kilobits per second throughput when I could connect where I should have seen 30 to 70 Mbps. I fired up the Wi-Spy 2.4x to see what was the matter.

It seemed like I was seeing a lot of energy down at the lower end of the band even when the Extreme wasn’t transmitting. I switched to channel 11, and, magically, performance was restored. Now, according to iStumbler, no one is transmitting in channel 1, so there’s other ugliness involved. If you look at the Eakiu screen capture (at right), you can see the time sequence moving from newest to oldest on the Z axis (roughly front to back). I switched from channel 1 to 11 right where you see energy levels go down and red (higher dBm signals) disappear on the left, and start to fire up into red on the right. Clearly, something’s using that part of the 2.4 GHz band (amateur radio? electronic newsgathering? another licensed purpose? an ugly transmitter?). But without the Wi-Spy, I would have been slightly flummoxed.

The Wi-Spy isn’t for every network manager or hobbyist, but it’s going to help IT professionals and Wi-Fi busybodies like myself answer a lot of questions that are otherwise lost in the ether.

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August 7, 2007

Apple Upgrades AirPort Extreme to Gigabit Ethernet

By Glenn Fleishman

Apple slips in 1000 Mbps Ethernet in its Wi-Fi router: Apple quietly upgraded its Draft N-based AirPort Extreme Base Station to full gigabit Ethernet support across its three LAN and one WAN ports today. While the company didn’t release information separately, they contacted me to note the change, and the Apple Store’s product listing has been updated. The new base station can be ordered right now.

The first release of Apple’s Draft N base station was rather marvelous for its inclusion of a USB port to share multiple printers and hard drives; the company’s decision to have both 2.4 GHz and 5 GHz radios inside; and the fact that Macs had been shipping with 802.11n inside, requiring just an enabler, released with the base station, to upgrade their performance. My primary complaint, however, was the mismatch between the company’s widespread inclusion of GigE in most of its models long before the competition. With the drop in cost in GigE switches, it seemed odd for Apple to release a unit that was designed for homes and small offices that would underperform a $35 Ethernet switch.

I also suspected that the overall performance of the 802.11n draft that Apple is using was constricted due to internal Ethernet limits. In my testing for a review in Macworld, I was able to top 90 Mbps in Wi-Fi to Ethernet and Wi-Fi to Wi-Fi transfers. But Ethernet-to-Ethernet data was limited to just over 90 Mbps as well. Apple says that their new gigabit Ethernet base station is up to 50 percent faster for wireless-to-wired links, which would put it closer to 150 Mbps, a speed achieved on other GigE-based Draft N routers.

When testing the base station in February, I discovered that with NAT enabled to share access from an incoming WAN link, performance was restricted to about 30 Mbps from wireles LAN to LAN and 60 Mbps from wired LAN to WAN. Apple confirmed this was a bug that was due to performance issues in their NAT stack. Apple wasn’t able to tell me if this limitation has been fixed, but I would imagine so.

This bug emerges in only two edge cases: Where a broadband connection exceeds 30 Mbps, which is true for some fiber and cable customers; or where a corporate or office LAN isn’t supplying addresses to the computers connected via the AirPort Extreme. If NAT is turned off, the AirPort gateway has no performance limitations.

The price for the AirPort Extreme Base Station with Draft N remains $179.

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July 25, 2007

iPhones Didn't Bring Down Duke APs

By Glenn Fleishman

Cisco releases full details on problem at Duke: While widely reported that one or two Apple iPhones out of about 150 used on Duke University’s Wi-Fi network were bringing down groups of a dozen to 30 access points at one time, it turns out it was a Cisco fault all along that the iPhone triggered. A Duke assistant IT director initially blamed the iPhone for the problem. He later posted a note on his blog that he “regret[ted]” sounding quite so sure it was the iPhones’ fault.

Cisco’s security advisory, “Wireless ARP [Address Resolution Protocol] Storm Vulnerabilities,” explains how in a very particular set of circumstances, a mobile device moving between access points and retaining certain information could cause Cisco network controllers to produce a storm of ARP requests. When I first heard about this problem in email from Miller—I declined to write about this because I thought it was too speculative at the time—the 18,000 ARP requests being made per second seemed like far too high a number to be produced over a wireless connection by a single mobile device.

While the advisory doesn’t cite the Duke situation, the company confirmed that the Duke situation was what triggered this advisory and update, according to Network World.

The iPhone is now in the clear as the culprit, just the trigger. It’s likely we’ll see more vulnerabilities and bugs show up, however, because of the extreme mobility and promiscuity of the iPhone. It’s willing to connect to any network it knows whenever it sees it, and to hop off onto EDGE whenever the network performance drops too low.

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June 7, 2007

Meraki Details Outdoor Repeater, Solar Charger

By Glenn Fleishman

Meraki’s recently announced outdoor repeater with optional solar/battery power could transform grassroots networks: Meraki has established itself as the cheapest provider of hardware and back-end controller support for mesh networking. With its $50 indoor nodes and new $100 outdoor repeater (shipping in July), the firm is making good use of its $5m in investment from Google and Sequoia Capital.

In an interview this week with co-founder and chief executive Sanjit Biswas, I discovered that despite the low cost, Meraki is “actually able to seel these devices at a small profit,” Biswas said. The insides of a Meraki router are pure commodity, rather close to what’s found in an inexpensive Linksys, he said. “We spent a lot of time studying the economies of scale opened up by them.”

Biswas noted that he and his co-founders were graduate students for the five years prior to starting Meraki, and had to hack small, cheap gear by necessity. In the process, they put the software intelligence—the controlling part of the network—into remote servers, leaving individual devices to act as relatively low-powered nodes in a network that would self-form as it grew.

The new outdoor repeater is designed to allow those network to expand even further. With a built-in antenna that offers higher gain than their indoor node, they expect a range of several hundred feet. Optional higher-gain antennas can be installed, too. “Really what we’re doing is saying, hey, we’re a software company; if you want to tinker with the hardware and pick up some long-distance antennas, then we’re all for it,” Biswas said. Some customers have already set up 10 to 12 km links with the pre-release versions of the repeater.

The Meraki Outdoor has two 10/100 Mbps Ethernet ports to allow local networks to be tied in or to run back-to-back repeaters with highly directional antennas. For now, each device has a single radio, but Meraki—like virtually all wireless LAN and mesh/metro firms—uses Atheros chips, and Atheros recently announced their roadmap with a reference design for an access point with two separate radios.

Meraki’s outdoor devices are highly ruggedized, Biswas noted. “We designed the outdoor to survive anything from a monsoon to a scandinavian winter—pretty robust conditions.” Meraki’s equipment is already used in 1,000 networks around the world, and there’s already a need for the outdoor product to spread coverage from the inside out, as Biswas explained.

The firm developed its own custom routing protocol that builds on top of the 802.11 set of standards. This allows each node to receive and send normal Wi-Fi traffic while also transferring control information. Their mesh routing system optimizes to reduce interference rather than for the highest thorughput. “People in general using Internet access only use tens to hundreds of kilobits per second when you average it out,” Biswas said in the kinds of installations their gear is used in. Groups of mesh nodes can switch channels to improve network quality or increase throughput, however.

The intelligence of the system lies in Meraki’s servers—these servers provide controller features that can cost thousands of dollars with other mesh or large-scale networks on top of the higher cost of each node. Even Ruckus’s recently announced small-to-medium-sized business networking equipment requires a controller that starts at $1,200 for a small number of access points. (Ruckus is focusing on throughput and signal efficiency, however, for ensuring the best quality of service with streaming, voice, and overall data transfer.)

While the mesh nodes exchange information about path efficiency, Meraki’s servers handle auto-discovery, collect statistics, and provide remote management. This means that any cluster of Meraki nodes—any group of nodes on a unique channel—must have its own backhaul. But because the system is self reconfiguring, no network will accidentally sever itself by losing an Internet feed on a segment.

Each Meraki network becomes its own cloud of access with unique private addresses assigned persistently to devices that join the network. This allows someone to roam from node to node, and it also allows multiple injection points—nodes connected to an Internet feed—to allow aggregating of bandwidth. Each TCP/IP connection can be routed the most efficient way through the network. The system can also packet-shape and throttle, allowing each node to control how much of its bandwidth is used by the Meraki network. That’s a critical factor when shared DSL or other connections are being tied into a network.

The outdoor repeater includes power over Ethernet (PoE) as a standard feature, including the necessary adapter. This can allow an Ethernet cable to be used to provide juice to an outdoor node that’s not sited near an electrical outlet. Using electricity outdoors or on rooftops is always a tricky civic code issue, too, making PoE a better choice.

The solar charger/battery combination that will be offered for the outdoor repeater should allow use in places where electricity and Ethernet just isn’t an option, whether on a condo rooftop, on a savannah, or in a park. Biswas said that they were fortunate to have on their team the right combination of engineers to slice the cost of the device down to roughly $400 from $1,000. The final price hasn’t been set. “This is almost a hobby project we had running internally,” Biswas said.

Solar panels are actually in short supply, driving up the cost. Through use of a custom charge controller built in house, Biswas said they cut the panel size to a third of their initial requirements. They also built Ethernet into the controller, allowing it to handle reporting of a range of statistics back to their servers. This will allow network operators to pull useful details about the panel and its battery without making a remote visit.

The batteries are lead-acid, which have a number of downside compared to lithium-ion, but which are relatively cheap and available worldwide in the right format to be replaced out on site without expensive international shipments of custom items. “We’re able to use batteries that are used in security systems around the world,” Biswas said.

With a battery-operated Meraki Outdoor node being recharged by solar panels, network builders of all stripes are freed from a grid requirement. Biswas said that their work on a growing free network in San Francisco led them to see this as a developed-world problem, not just a developing-world one. His customers “want us to deploy larger and larger networks; they were having trouble with the power because it’s a sticking point. People would get hung up on, hey, I’m putting a power outlet on your roof,” he said.

(The San Francisco network has seen over 3,000 users during its operation iwth about 250 to 300 users on during peak periods. It covers about a square mile, and it’s let the company get their hands dirty, Biswas said.)

Their new outdoor product may be the biggest challenge yet to the more expensive—but more robust—nodes sold for thousands of dollars by metro-scale equipment makers like Tropos and SkyPilot. Biswas said that they weren’t attempting to challenge these firms in the municipal market yet, as they have no public-safety offering, and don’t view their equipment as resilient enough for that yet. Tropos, he noted, offers bullet-proof casings for their nodes. “They’re hooking them up to cameras and people do shoot at these things.”

For now, Meraki’s early customers are entirely through word of mouth. The firm has no sales department, and continues to devote most of its efforts to extending its product line, and getting nodes into the field. I see remarkable potential for small networks to be built easily by neighborhood groups, community organizations, and business associations—and then later linked up with either more Meraki equipment or higher-end metro-scale gear.

Whatever the case, Meraki has broken the price barrier and dropped the complexity bar. Will a million neighborhood networks bloom?

Posted by Glennf at 11:48 AM | Comments (1) | TrackBack

June 4, 2007

Meraki Extends Range with Repeater, Solar Power

By Glenn Fleishman

Meraki introduces two additional models to its inexpensive mesh routing line-up: Meraki is interested in simplicity, fungibility, and quantity. Added to their existing $49 interior mesh node, which can plug into a connection and share it through automatic discovery of other nodes, they’ve announced a $99 repeater designed to be hung outdoors and reach up to 700 feet without an optional high-gain antenna. The Meraki Outdoor needs no wired feed, although it comes with double Ethernet ports.

The Meraki Solar (price to come) will power the Meraki Outdoor, making external, electricity-free mesh routing a reasonable option in both U.S. neighborhoods and developing rural economies. In the U.S., the issues over first, getting the rights to site equipment on a utility pole, and, second, getting electricity to equipment on a pole seem to be stalling networks of all kinds across the country. (This is one reason why Qualcomm and cell companies were laughing at muni Wi-Fi and mobile WiMax in their early days: they were thinking how naive the nascent industries were about real estate.)

With a solar-powered outdoor node with a high-gain antenna and a decent line of sight—read up on the Fresnel zone for those issues—this could allow a neighborhood area network (NAN) that wanted to use, say, a Speakeasy go-ahead-and-share-it T-1 or DSL line to set up a network pretty easily. I have been asked many times over the years by NANs what equipment to buy—if it all checks out, Meraki’s going to have a lock on that market, too.

Posted by Glennf at 9:42 AM | Comments (2) | TrackBack

May 21, 2007

Atheros Expands Draft N Options with USB, Routers

By Glenn Fleishman

Atheros announces fast, two-radio gateway, USB adapter, revised single-radio gateway: Chipmaker Atheros announced today that it has dramatically expanded the variety of its Draft N reference designs to include the smallest form factor USB 2.0 after-market adapter and two new routers, including a dual-radio access point that can achieve 400 Mbps in aggregated TCP/IP throughput. Reference designs are licensed to manufacturers which modify and package them as unique products.

Atheros faces sharp competition from Airgo, Broa