Geez Patrick, go to bed!!! Get some rest!!!!
Seriously, this is a great list. Definitely shows how the VL is a
completely different animal than the other options out there.
Matt Larsen
[EMAIL PROTECTED]
Patrick Leary wrote:
I believe most if not all of the below are features not found among
Trango or Canopy. I list a few of the advanced features. A few of
these (probably some you have never heard of before or even thought
of) I show in detail. Maybe this post will also explain why the VL is
not simply an Atheros chipset in a case and why it is not simply some
basic CSMA/CA. This is just a small sampling. The manual, with lots of
tables, drawings, etc., is 277 pages of which most relate to things
that can be configured/optimized. (I can send the pdf to any who want
it.)
· Chassis-based or stand alone AUs with multiple LEDs on the chassi
blade versions, including current consumption
· Redundant power supplies with status LEDs, including over
temperature warning
· GPS-sync module (for hoppers) also can be used for VL for their
alarm capabilities
· 110vAC or -48vDC power options
· Built-in Ethernet repeater in the chassis blades to support over 600
feet from network switch/router to ODUs
· AUs with antenna options, including built-in 60, 90, or 120 degree
sectors plus options with external connector
· OFDM (with FEQ) for NLOS ability to enable connection of more of the
potential subscriber population
· Adaptive modulation with configurable minimum modulation
· Up to 40Mbps net (ftp) per sector
· Over 40,000pps with small packets
· No loss in capacity with varying frame size (all other UL gear
capacity is dramatically reduced when passing small packets
· FIPS 197 option. AES standard, no extra charge
· Virtual LANs based on IEEE 802.1Q with standard QinQ built-in support
· Layer-2 traffic prioritization based on IEEE 802.1p and layer-3
traffic prioritization based on either IP ToS Precedence (RFC791) or
DSCP (RFC2474). It also supports traffic prioritization based on UDP
and/or TCP port ranges. In addition, it may use the optional Wireless
Link Prioritization (WLP) feature to fully support delay sensitive
applications, enabling Multimedia Application Prioritization (MAP) for
high performance voice and video. (MAP can increase VoIP capacity by
as much as 500%)
· Built-in surge suppression in both ODU and IDU
· Full management of all components, from any point in the system.
· Components can be managed using standard management tools through
SNMP agents that implement standard and proprietary MIBs for remote
setting of operational modes and parameters. Security features
incorporated in BreezeACCESS VL units restrict access for management
purposes to specific IP addresses and/or directions, that is, from the
Ethernet and/or wireless link.
· True toll quality VoIP (MOS of 4.1 or better)
· Upload new or updated configuration file to multiple (selectable)
units simultaneously, thus radically reducing the time spent on unit
configuration maintenance.
· Back up/shadow flash, can support two different versions of firmware
· 5MHz (4.9GHz version), 10MHz, or 20MHz channel options.
· SUs autorecognize and configure channel size
· SUs available with external connector or integrated 21dBi with
10.5h/10.5v beamwidth
· Multilevel password, multi-layer ESSIDs
· Configuration of remote access direction (from Ethernet only, from
wireless link only or from both)
· Configuration of IP addresses of authorized stations
· Numerous LEDs detailing advanced status information, plus tri-color
10-bar alignment LEDs that directly corresponds to SNR, including
amber for warning signal is too strong (SNR >50dB)
· Pole mount or band strap mounting options, hardware included
· Power supply included, with reset feature and integrated surge
suppression
· Specialty Cat 5 connector
· Industrial grade waterproof seal with O rings
· Auto or configurable maximum cell distance
· Automatic distance learning. Per SU Distance Learning mechanism
controlled by the AU enables each SU to adapt its Acknowledge timeout
to its actual distance from the AU, minimizing delays in the wireless
link
· Low Priority Traffic Minimum Percent feature ensures a selectable
certain amount of the traffic is reserved to low priority packets to
prevent starvation of low priority traffic when there is a high demand
for high priority traffic.
· MAC address deny and allow list
· Able to configure size of concatenated frames (enables
customization/optimization based on expected applications)
· Best AU and preferred AU options in the SUs. (Best AU explanation:
each of the AUs can be given a quality mark based on the level at
which it is received by the SU. The SU scans for a configured number
of cycles, gathering information from all the AUs with which it can
communicate. At the end of the scanning period, the SU reaches a Best
AU decision according to the information gathered. The AU with the
highest quality mark is selected as the Best AU, and the SU will
immediately try to associate with it. The quality mark given to each
AU depends on the level at which it is received by the SU. The Best AU
selection mechanism can be overridden by defining a specific AU as the
preferred AU.)
· Broadcast rate limiting, selectable
· Configurable threshold for lost beacon watchdog
· Support of packet sizes to 1600 bytes, including VLAN(s) for single
or double-tagged packets
· Advanced event log feature. The event log is an important debugging
tool and a flash memory sector is dedicated for storing it. Events are
classified according to their severity level: Message (lowest
severity), Warning, Error or Fatal (highest severity). The severity
level of events that should be saved in the Event Log is configurable.
Events from the configured severity and higher are saved and may be
displayed upon request. Log history can be displayed up to the full
number of current active events. In the log, an event is defined as
active as long as it has not been erased (a maximum of 1000 events may
be stored). The Event Log may be read using TFTP, with remote file
name <SNMP Read Community>.log (the default SNMP Read Community is
“public”). The Event Log may also be uploaded to a remote FTP server.
The Event Log Menu includes the following options: Event Log Policy,
Display Event Log, Erase Event Log, Event Load Upload
· Multiple DHCP options: From Wireless Link Only, From Ethernet Only,
From Both Ethernet and Wireless Link
· Intelligent ATPC (The algorithm is controlled by the AU that
calculates for each received frame the average SNR at which it
receives transmissions from the specific SU. The average calculation
takes into account the previous calculated average, thus reducing the
effect of short temporary changes in link conditions. The weight of
history (the previous value) in the formula used for calculating the
average SNR is determined Menus and Parameters Operation and
Administration by a configurable parameter. In addition, the higher
the time that has passed since the last calculation, the lower the
impact of history on the calculated average. If the average SNR is not
in the configured target range, the AU transmits to the SU a power-up
or a power-down message. The target is that each SU will be received
at an optimal level, or as high (or low) as possible if the optimal
range cannot be reached because of specific link conditions. Each time
that the SU tries to associate with the AU (following either a reset
or loss of synchronization), it will initiate transmissions using its
Transmit Power parameters. If after a certain time the SU does not
succeed to synchronize with the AU, it will start increasing the
transmit power level. In an AU the maximum supported transmit power is
typically used to provide maximum coverage. However, there may be a
need to decrease the transmitted power level in order to support
relatively small cells and to minimize the interference with the
operation of neighboring cells, or for compliance with local
regulatory requirements. In some cases the maximum transmit power of
the SU should be limited to ensure compliance with applicable
regulations or for other reasons.
· And ATPC is highly configurable (only highly advanced operators
should do so), with parameters like: ATPC min. SNR level, ATPC Delta
from min. SNR level, Min. interval between ATPC messages, ATPC power
level change step (1-20dB with default of 5dB)
· Advanced Transmit Control. The Tx Control option enables turning
Off/On the AU’s transmitter, or having the AU Tx status controlled by
the status of the Ethernet port/link.
· Cell Distance Mode feature: The higher the distance of an SU from
the AU that is serving it, the higher the time it takes for messages
sent by one of them to reach the other. To ensure appropriate services
to all SUs regardless of their distance from the AU while maintaining
a high overall performance level, two parameters should be adapted to
the distances of SUs from the serving AU: The time that a unit waits
for a response message before retransmission (ACK timeout) should take
into account the round trip propagation delay between the AU and the
SU (The one-way propagation delay at 5 GHz is 3.3 microseconds per
km/5 microseconds per mile.). The higher the distance from the AU of
the SU served by it, the higher the ACK timeout should be. The ACK
timeout in microseconds is: 20+Distance (km)*2*3.3 or 20+Distance
(miles)*2*5. To ensure fairness in the contention back-off algorithm
between SUs located at different distances from the AU, the size of
the time slot should also take into account the one-way propagation
delay. The size of the time slot of all units in the cell should be
proportional to the distance from the AU of the farthest SU served by
it. The Cell Distance Mode parameter in the AU defines the method of
computing distances. When set to Manual, the Maximum Cell Distance
parameter should be configured with the estimated distance of the
farthest SU served by the AU. When set to Automatic, the AU uses a
special algorithm to estimate its distance from each of the SUs it
serves, determine which SU is located the farthest and use the
estimated distance of the farthest SU as the maximum cell distance.
The value of the maximum cell distance parameter (either computed or
configured manually) is transmitted in the beacon messages to all SUs
served by the AU, and is used by all units to calculate the size of
the time slot, that must be the same for all units in the same sector.
When the Per SU Distance Learning option is enabled, the AU uses the
re-association message to send to each SU its estimated distance from
the AU. The per-SU distance is used to calculate the ACK timeout to be
used by the SU. When the Per SU Distance Learning option is disabled
(or if it cannot be used because the SU uses a previous SW version
that does not support this feature), the SU will use the maximum cell
distance to calculate the ACK timeout. The AU always uses the maximum
cell distance to calculate the ACK timeout. It should be noted that if
the size of the time slot used by all units is adapted to the distance
of the farthest unit, then no unit will have an advantage when
competing for services. However, this reduces the overall achievable
throughput of the cell. In certain situations, the operator may decide
to improve the overall throughput by reducing the slot size below the
value required for full fairness. This means that when there is
competition for bandwidth, the back-off algorithm will give an
advantage to SUs that are located closer to the AU. The Cell Distance
Parameters menu includes the following parameters: fairness factor,
per SU distance learning, show cell distance parameters.
· Arbitration Inter-Frame Spacing feature
· Max association feature
· Wireless Link Trap Threshold feature: defines the threshold for the
wireless quality trap, indicating that the quality of the wireless
link has dropped below (on trap) or has increased above (off trap) the
specified threshold. The Wireless Link Trap Threshold is in percentage
of retransmissions, and the allowed range is from 1 to 100 (%). The
default is 30 (%).
· Lost Beacons Transmission Watchdog Threshold feature: When it is
unable to send beacon frames for a predetermined period of time, such
as in the case of interferences, the AU resets itself. The Lost
Beacons Transmission Threshold parameter represents the number of
consecutive lost beacons after which the unit will reset itself. The
range for this parameter is 100 – 1000 or 0. When the parameter is set
to 0, this feature is disabled, i.e. internal refresh will never be
performed. The default value is 218.
· Disassociate (AU only) feature: enables disassociating all SUs
associated with the AU or a selected SU. This feature is useful during
configuration changes, enabling to force the SU(s) to re-initiate the
association process, including the search for the best AU (or a
preferred AU) using the Best AU process, without performing a full
reset. The Disassociate submenu includes two options: Disassociate All
SUs, Disassociate SU By MAC Address: to disassociate a selected SU.
· Configurable Minimum and Maximum Contention Windows (The
BreezeACCESS VL system uses a special mechanism based on detecting the
presence of a carrier signal and analyzing the information contained
in the transmissions of the AU to estimate the activity of other SUs
served by the AU.) The available values are 0, 7, 15, 31, 63, 127,
255, 511 and 1023. A value of 0 means that the contention window
algorithm is not used and that the unit will attempt to access the
medium immediately after a time equal to DIFS. The default min. value
is 15. The default max. is 1023.
· Advanced MIR/CIR (controlled by both the SU and AU) with special
configurable graceful degradation algorithm ensuring that the
degradation of performance for each individual SU is proportional to
its CIR.
Patrick Leary
AVP WISP Markets
Alvarion, Inc.
o: 650.314.2628
c: 760.580.0080
Vonage: 650.641.1243
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