Updated 8/12/2010: Added link to six location wireless test article
TRENDnet decided to make a liar of me and ship the first three-stream (450 Mbps maximum link rate) N router to become available. So as soon as it came in, I put it on the test bench to see what, if any, improvement three stream N offers over two-stream. But first, let's take a quick look at the hardware.
The 691GR looks like many of TRENDnet's other wireless routers, coming packaged in a glossy-black plastic case. The only ventilation holes are on the side of the case and a vertical stand doesn't come with the router. So, as you might expect, it gets a tad warm, even when sitting idle.
The rear view in Figure 1 shows the three non-upgradeable antennas, single WAN and four switched LAN ports and Power and WLAN switches. All Ethernet ports are 10/100/1000 and there's also a WPS pushbotton on the left side panel.
Figure 1: TRENDnet TEW-691GR rear view
Figure 2 shows the FCC ID photo (FCC ID XU8TEW691GR) for the board. It uses a Ralink RT3883F 802.11n 2.4/5GHz 3T3R 450/450Mbps Single Chip AP/Router SoC. This is Ralink's second pass at a three-stream N chip, replacing the RT2883 used in first generation routers that never shipped.
Figure 2: TRENDnet TEW-691GR board
You can also see an Atheros device, but it's an AR8316 Gigabit switch, which handles the single WAN and four LAN 10/100/1000 Ethernet ports. A Winbond W9751G6JB provides 64 MB of RAM and a Macronix 29LV640 adds 8 MB of flash. The three small devices surrounded by RF shields are SST12LP15A's, which are 2.4 GHz amplifiers.
Although the three antennas are connected to the board via mini connectors (Hirose U.FL, I think), there are no rear-panel connectors. So there is no easy antenna upgrade path.
Note while the Ralink chip is a dual-band device, there is no option in the admin GUI to switch to 5 GHz. And even if there were, the aforementioned 2.4 GHz amplifiers would prohibit its use anyway.
As a final construction note, I opened up my sample and found that the FCC photo is accurate in that neither the Ralink nor Atheros devices have heatsinks.
I'll do a more complete runthrough of the 691GR's features when I post the full review. But I thought you'd like to see the wireless controls that TRENDnet provides in the meantime. Figure 3 shows the Basic wireless settings. Note the multiple SSIDs, which would let you set up guest networks. Each SSID can have its own wireless security settings. But there are no settings for controlling access to the wired or other wireless LANs.
Figure 3: TRENDnet TEW-691GR Basic Wireless controls
WDS is also supported, which the online help says is implemented in repeating mode, without the option to switch to bridging only mode.
The full-sized image shows the HT Physical Mode controls, which include Channel Bandwidth, Guard Interval, MCS and Extension Channel. Of these controls, the only ones you'll likely need to play with are the Channel Bandwidth (to kick it up to full 450 Mbps mode) and Extension Channel (if you want to try to be more neighbor friendly when using Channel 6 and Auto 20/40 MHz mode).
The MCS setting lets you force the maximum link rate used if you think that will help you get a better performing connection (it most likely won't). Values supported are MCS 0-15 and 32 and, of course, the default Auto mode. The MCS index table shown in Figure 4 is a bit hard to follow. But note the second column (Number of spatial streams).
Figure 4: MCS index table (courtesy Agilent Technologies)
MCS 16-23 contain values for the three spatial streams required to achieve the maximum 450 Mbps link rate (MCS 23). But the MCS control doesn't include these values. Note that you'll get a maximum link rate of 217 Mbps in the default 20 MHz channel bandwidth mode.
The router's Help file contains a reference to an Operating Mode control that TRENDnet wisely removed from the GUI. The settings of Mixed Mode and Green Field would likely have confused people and just given them one more control that was more likely to screw them up vs. helping improve performance.
Advanced wireless settings are shown in Figure 5. The most useful control here is the Transmit power, which has Full (default), Half and Low settings.