Cannot connect using 802.11n

N is not a standard. If you don't use equipment from the same manufacturer and of the same draft # (Like SysExpert said) don't expect it to work better than G. And many times worse.
See http://en.wikipedia.org/wiki/IEEE_802.11n

Darr247: Thanks a lot for the very careful explanation. The driver updated flawlessly to a March/08 version (vs my previously installed 2006 version), but problems still remain. I can only connect at max of 36mbps and connection keeps changing speed. Effective transfer rates in the range of 4Mbps only. I think I will have to fuss much deeper into configuration details...

Are 802.11n draft versions 2.0 and 1.0 compatible with each another? My router says it is a 2.0 and I don't know about my notebooks.

Effective transfers are well below 802.11g, at only 4Mbps vs 12Mbps of by wired connections to the same notebooks.

Even though the router only works at 2.4GHz (I'm concluding this because it doesn't seem to support 802.11a), it does offer the option of working at "20MHz+40MHz auto". Shouldn't that be enough?

I agree the problem is the router somehow. I switched back to my old 802.11g router and got wireless download speeds of full 12Mbps (my cable speed) vs 4Mbps in this new one.

The Belkin N1 Vision is pretty poor in configuration options anyway, despite being currently their most premium router. My old D-Link DGL-4300 offers a ton more configuration options.

But shouldn't I at least get 802.11g speeds? I'm getting mediocre 4Mbps....

If you could take a look, attached is a Word doc with a print screen of the router's wireless configuration web page.

Thanks. Situation improved marginally. File transfers (both internet downloads - which are externally capped at 12Mbps and within my network) are running at 9-11Mbps. That's 802.11b speeds, but at least on the upper end of it rather than on the lower end as before. Still nothing close to 802.11g (let alone n....).

Any other ideas? Are you familiar with the network card driver settings as I outlined in my original question? Should I change anything there?

I managed to get up to 18Mbps by repositioning the antennas and turning off 802.11n on all the adapter cards. But that is as much as I will get. I'm convinced the biggest culprit is the router itself. All reviews I could find on the web are bashing this router for mediocre performance.

That's what you get for buying something straight at the store without reading reviews first. At almost US$200, at thought I was getting something really state-of-the-art. Stay away from Belkin. Looks has nothing to do with performance.

I'm accepting your previous answers since they helped me narrow down the problem and maximize to the extent possible. Thank you!

On the Dell, here are some settings you could tweak one at a time to see if they help:

- Afterburner: Disabled
- AP Compatibility Mode: Higher Performance (alt: broader compatibility)
- Minimum Power Consumption: Enabled
- XPress (TM) Technology: Disabled


Here's an explantion of the settings I found somewhere for a similar (but non draft-n) card:
802.11h+d
 
 The 802.11h+d property configures the advanced radio control of the WLAN card
 by an associated access point. The controls are enabled when the 802.11h+d property
 is set to Loose 11h, Loose 11h+d, or Strict 11h. When the setting is Strict 11h, the
 Dell Wireless WLAN Card associates only to access points supporting IEEE 802.11h
 protocols when operating in regions with special restrictions on radio operation.
 When the setting is Loose 11h, the WLAN card does not restrict associations based
 on the access point IEEE 802.11h support. When the setting is Loose 11h+d, the
 Dell Wireless WLAN Card does not restrict associations based on the access point
 IEEE 802.11h or IEEE 802.11d support.


Disabled (default)
Loose 11h
Loose 11h+d
Strict 11h



Afterburner

 Afterburner is a Broadcom proprietary high-performance implementation of a faster
 throughput added to wireless products that conform to IEEE 802.11g.

Disabled (default). Disables Afterburner.
Enabled. Enables Afterburner



Antenna Diversity
 Antenna Diversity is a function included in most wireless LAN equipment that has two
 antennas, Main and Aux. When set to Auto, Antenna Diversity monitors the signal from
 each antenna and automatically switches to the one with the better signal.

Auto (default).
Aux.
Main.



Band Preference
 The Band Preference property is available only on Dell Wireless WLAN Card models that
 have dual-band capability. Band Preference allows users to specify the IEEE 802.11
 band preference while roaming . This allows the wireless client to associate with
 another AP based on band preference even if the signal from the currently associated
 AP is strong enough to sustain the association .

None (default). Roams without regard to the frequency band of the available APs.
Prefer 802.11a (5 GHz band)
Prefer 802.11g/b (2.4 GHz band)



Bluetooth Collaboration
Bluetooth Collaboration enables general purpose input/output transmit suppression
protocol between the IEEE 802.11 media access control (MAC) and an external Bluetooth
chip to minimize transmit interference. Bluetooth Collaboration is enabled by default.

Enable (default)

Disable

BSS Mode
BSS mode is used to to restrict the IEEE 802.11b/g band to IEEE 802.11b only mode.
BSS Mode applies to networks that are configured for access points.

Default (default)

802.11b Only



Disable Upon Wired Connect
If this property is set to Enabled, whenever your computer is connected to an Ethernet
port and the link state is good, the computer automatically turns off the IEEE 802.11 radio.
This conserves IP address allocation, reduces security risks, resolves dual interface routing issues, and prolongs battery life.

Disabled (default)

Enabled



IBSS Allowed
This property must be set to Enabled for you to use the Dell Wireless WLAN Card Utility
or Wireless Network Wizard to create or connect to an ad hoc network. Your network
administrator may require this property to be set to Disabled for security reasons.

Enabled (default)

Disabled



IBSS 54g(tm) Protection Mode
A mechanism of prefixing each OFDM data frame with a request to send/clear to send
(RTS/CTS) complimentary code keying (CCK) frame sequence. The duration fields of
the RTS and CTS frames should allow the IEEE 802.11b node to correctly set its network
allocation vector (NAV) and avoid collisions with the subsequent OFDM frames. As required
for Wi-Fi®, protection mechanisms are enabled automatically whenever an IEEE 802.11b
STA joins the BSS. If no IEEE 802.11b STA joins, then no protection mechanism is used
and full IEEE 802.11g performance is attained.

Auto

Disabled



IBSS Mode
IBSS Mode is used to set the connection type in an ad hoc network. The following options are available:

802.11b Mode (default). Links only with IEEE 802.11b networks at the highest rate. Also, it excludes IEEE 802.11g networks.

802.11g Mode. Links only with IEEE 802.11g networks at the highest rate.



AP Compatibility Mode
Some older APs may have implementations that deviate from IEEE 802.11 standards.
Setting this property to Broader Compatibility enables your Dell Wireless WLAN Card to
better communicate with such APs, but at the expense of some performance loss.
The default setting is Higher Performance.

Higher Performance (default)

Broader Compatibility



Locally Administered MAC Address
Locally Administered MAC Address is used to override the MAC address of the Dell
Wireless WLAN Card. The Locally Administered MAC Address is a user-defined MAC
address that is used in place of the MAC address originally assigned to the network
adapter. Every adapter in the network must have its own unique MAC address. This
locally administered address consists of a 12-digit hexadecimal number.

Value. Assigns a unique node address for the adapter.

Not Present (Default). Uses the factory-assigned node address on the adapter.

The appropriate assigned ranges and exceptions for the locally administered address include the following:

The range is 00:00:00:00:00:01 to FF:FF:FF:FF:FF:FD.
Do not use a multicast address (least significant bit of the high byte = 1).
Do not use all 0s or all F's.



Location
Users who purchased their Dell Wireless WLAN Card in the United States have USA
as the default location; users who purchased their Dell Wireless WLAN Card in Japan
have Japan as their default location. For all other users, the Location property is not
available. See Radio Approvals for additional information.



Manage Wireless Settings
When the Manage Wireless Settings property is enabled, the Let this tool manage
your wireless network settings check box on the Wireless Networks tab of the Dell Wireless WLAN Card Utility is selected.

Enabled (default)

Disabled



Minimum Power Consumption
When enabled, this property enables the wireless client to either turn off
the radio or to not scan when the wireless client network is unassociated
or when the computer is in the IDLE state.

Enabled (default)

Disabled

PLCP Header
PLCP Header is used to set the header type used for CCK rates. The type
can be Long or Auto (short/long).

Auto (Short/Long) (default)

Long



Power Save Mode
The Power Save Mode property is used to put the wireless client computer
into the IEEE 802.11 Power Save mode. When the Power Save Mode property
is enabled, the radio is periodically powered down to conserve power. When
the radio is in Power Save Mode, packets are stored in the AP until the radio
comes on. The Fast setting allows full throughput with power savings.

Fast (default)

Enabled

Disabled



Radio Enable/Disable
When the value of this property is set to Disabled, the radio is turned off.
It may be necessary at times to turn off the radio to comply with restrictions
prohibiting the emission of radio signals, such as during takeoff and landing
onboard a commercial aircraft. Changing the value to Enabled turns the radio
back on. Certain computers may have other more convenient methods for
turning the radio on and off. Refer to operating manual that came with the
computer to see if such features exist.

Enabled (default)

Disabled

Rate
This property allows you to specify the rate (in Mbit/s) at which data is transmitted.
The possible values are: 1, 2, 5.5, 6, 9, 11, 18, 24, 36 48, and 54 . The default is
set to Use best Rate. This setting automatically adjusts the transmission rate to the
optimal rate based on the capabilities of the other wireless clients and access points.

  NOTE: The default value for this property is set for maximum performance. Therefore,
it is not recommended for home users to change the value. Only network administrators
or technicians with wireless LAN experience should attempt to make any changes.
 



Rate (802.11a)
This property allows you to specify the rate (in Mbit/s) at which data is transmitted
for IEEE 802.11a operation. The possible values are: 6, 9, 12, 18, 24, 36, 48, and 54.
The default is set to Use best Rate.

  NOTE: The default value for this property is set for maximum performance. Therefore,
it is not recommended for home users to change the value. Only network administrators
or technicians with wireless LAN experience should attempt to make any changes.
 


Rate (802.11b/g)
This property allows you to specify the rate (in Mbit/s) at which data is transmitted for
IEEE 802.11b/g operation. The possible values are: 1, 2, 5.5, 6, 9, 11, 18, 24, 36 48, and 54 .
The default is set to Use best Rate.

  NOTE: The default value for this property is set for maximum performance. Therefore,
it is not recommended for home users to change the value. Only network administrators
or technicians with wireless LAN experience should attempt to make any changes.
 



Disable Bands
This property is available only on Dell Wireless WLAN Card models that have dual-band capability.

None (default)

Disable 802.11g/b

Disable 802.11a



Fragmentation Threshold
The maximum size in bytes at which packets are fragmented and transmitted a piece at a
time instead of all at once. Available values range from 256 to 2346. The default value is 2346.



Roaming Decision
The signal strength value that determines when the Dell Wireless WLAN Card starts scanning for other APs.

Default (default). 75 dB

Optimize Bandwidth. 65 dB

Optimize Distance. 85 dB



Roam Tendency
This property adjusts the roaming thresholds for the Dell Wireless WLAN Card.

Moderate (default). Roams to APs having a signal strength at least 20 dB greater than the current access point.

Aggressive. Roams to APs having a signal strength at least 10 dB greater than the current access point.

Conservative. Roams to APs having a signal strength at least 30 dB greater than the current access point.



RTS Threshold
If the number of frames in the data packet is at or above the RTS Threshold,
a request to send/clear to send handshake is turned on before sending the
data packet. The default value is 2347. The range is 0 to 2347.



SSID Autopromote
If you used the Wireless Network Wizard or the Wireless Network Connection
Settings tool to connect to wireless networks, each network that you have
connected to is listed under Preferred network connections on the Wireless
Networks tab of the Dell Wireless WLAN Card Utility. Each time you start your
computer, the computer automatically attempts to connect to the network at
the top of the list. If that network is within range, the connection is made. If it
is not within range, your computer attempts to connect to the next network
on the list, and continues the process until it finds a network that is within
range. You can move any preferred network up or down the list.

If the SSID Autopromote property is disabled, you can manually override the
automatic network connection process and connect to the network of your choice,
regardless of its position on the list (see "Utility Controls"). If the SSID Autopromote
property is enabled, you cannot manually override the automatic connection process.

Disabled (default)

Enabled



VLAN Priority Mode
The VLAN Priority Mode property controls the introduction of VLAN-tagged packets
to send priority information when your network connection is associated to non-QoS
infrastructure devices. When this property is set to Auto or On, the NDIS driver
always advertises QoS regardless of whether the WMM property is enabled or disabled.

On transmit, when this property is set to On, and the Afterburner property is disabled,
and the packet does not already contain a VLAN tag, and the priority is nonzero, and
the association is non-WMM, a Priority tag is added to the 802.11 packet.

On reception, when this property is set to On, and the Afterburner property is disabled,
and the packet has a VLAN tag, and the VLAN ID is zero, the VLAN tag is stripped, and
the priority from the tag is assigned to the packet. This stripping is done whether or not
the association is WMM because WMM appendix A.6 indicates that WMM STAs must be
able to accept VLAN-tagged packets.

Auto (default)

On

Off



WMM
Wi-Fi Multimedia (WMM"). The WMM property enables quality of service for audio,
video, and voice applications over a wireless network by prioritizing streams of content
and optimizing the way the network allocates bandwidth among competing applications.

Auto (default). With WMM set to Auto, when the wireless client connects to the AP, and
the AP has Unscheduled Automatic Power Save Delivery (UAPSD) enabled, the wireless
client is allowed to enter Power Save mode.

Enabled. The wireless client enters Power Save mode for WMM associations independent
of whether the AP has UAPSD enabled or disabled.

Disabled. The wireless client does not have WMM association.



WZC IBSS Channel Number
The WZC IBSS Channel Number property selects the independent basic service set
(IBSS) channel number on which to operate when WZC is managing your wireless
networks. The default setting is 11.




WZC Managed Ethernet
If the WZC Managed Ethernet property enabled, Wireless Zero Configuration Service
(WZC) is enabled to manage 802.1x connections for Ethernet devices in your computer.
This setting only applies if the Dell Wireless WLAN Card Utility is enabled to manage your Dell Wireless WLAN Card.

Disabled (default)

Enabled



XPress (TM) Technology
Xpress" Technology is a proprietary frame bursting technology that improves
throughput by repackaging data so that more data can be sent in each frame.
Xpress" Technology is disabled by default.

Disabled (default). Disables Xpress" Technology.

Enabled. Enables Xpress" Technology.

Looks to be a driver problem.

I also had this problem on my Dell XPS using the Dell Wireless 1505 Draft 802.11n WLAN Mini-Card.
I was newly running Windows 7 64bit with the default driver available version 5.30.21.0.

It was configured to support 802.11a/b/g/n, but had limited 802.11n support. I could not see my 5G network and provide only slow connectivity on the 2.4G network.

Solution
Replace driver with Dell's Studio 1555 compatible WLAN driver version 5.60.18.8.

http://support.us.dell.com/support/downloads/download.aspx?c=ca&l=en&s=gen&releaseid=R242438&formatcnt=1&libid=0&typeid=-1&dateid=-1&formatid=-1&fileid=350705

To replace you will have to extract the driver to your computer and update it via the Windows device manager.
Select the folder that relates to you region when updating, e.g US locations use DRIVER_US.
The default settings provided immediate connection to the 5G network.

Basic router configuration:
Linksys wrt610N
5G
Mode:          Wireless-N Only
Channel Width:          40MHz only
Security:          WPA2-Personal

2.4G
Mode:          Mixed
Channel Width:          20MHz only  (Cisco does not allow 40MHz on 2.4G though the option was there)
Security:          WPA2-Personal