Berkeley Varitronics Systems Grasshopper User Manual

Grasshopper

manual version 2.0

Contents

GRASSHOPPER ACCESSORIES....................................................................................... 2

GRASSHOPPER KEYPAD............................................................................................... 2

GETTING STARTED...................................................................................................... 3

MAIN SCREEN........................................................................................................... 4

CHANNEL SCREEN...................................................................................................... 4

SELECT AP................................................................................................................ 5

APs ONLY................................................................................................................. 5

SCAN FOR APs.......................................................................................................... 5

SPECTRUM SCREEN.................................................................................................... 6

RSSI SCREENS.......................................................................................................... 6

PEAK HOLD.............................................................................................................. 6

PER........................................................................................................................ 7

PEAK...................................................................................................................... 7

CONTRAST ADJUSTMENT.............................................................................................. 7

BACKLIGHT ADJUSTMENT............................................................................................. 8

WEP ENCRYPTION DETECTION....................................................................................... 8

UPDATING GRASSHOPPER FIRMWARE............................................................................. 8

NETWORKING BASICS.................................................................................................. 9

DSSS INTERNATIONAL CHANNEL CHART........................................................................... 10

GLOSSARY OF ACRONYMS............................................................................................ 11

GENERAL SAFETY....................................................................................................... 12

ANTENNA RADIATION PATTERNS
GRASSHOPPER DATA SHEET

Page 1

Grasshopper™ is a handheld, wireless receiver
designed specifically for sweeping and optimizing Local
Area Networks. The instrument measures coverage of
direct sequence CDMA networks which operate on the IEEE

802.11b standard allowing the user to measure and deter­mine the AP (Access Point), PER (Packet Error Rate), and
RSSI signal levels aiding in locating the hub and access
points throughout a building. Grasshopper detects and dif­ferentiates from narrow-band multipath interferences such
as microwave ovens and frequency hopping systems and
features a built-in display, keypad and removable battery
pack for true portability.

Grasshopper uses common AA battery cells found in any
conveinence store. Ni-Cad, Alkalines, Ni-MH and Li-Ion
cells may all be used. Grasshopper does require 5 AA cells
with at least 1500 mAh per cell. BVS supplies 2 battery
packs complete with 10 Ni-MH battery cells to get users
working right out of the box. Ni-MH cells are recommend­ed for best performance from your Grasshopper.

Grasshopper also includes a simple 2.4 GHz threaded
antenna that screws right into the top of the unit. Additional
antennas may be ordered from BVS through BVS.

At the top of the Grasshopper rest the power switch, anten-
na connector and upload port. The power switch (left) is
a simple two way toggle switch. The antenna connector
(middle) is an SMA Female 50 ohm. The provided antenna
easily screws and unscrews from this connector. Be sure to
unscrew antenna when transporting the Grasshopper. The
upload port (right) is used as a one way communications
port for uploading new firmware to the Grasshopper. The
port uses the provided cable which employs a standard
RJ-11 phone jack on one end and DB-9 PC serial cable on
the other end.

See UPDATING GRASSHOPPER FIRMWARE in this manual
for firmware updating procedures.

Page 2

GRASSHOPPER ACCESSORIES

Your Grasshopper includes all basic operational accessories
including the following: antenna, battery pack charger (Ni­MH), spare battery pack (Ni-MH), AC/DC power cable, car­rying case and upload cable. Simply insert depleted battery
pack into charger and plug charger into AC outlet. See rear of
charger for LED status indicator lights. Approximate charging
time for included Ni-MH battery pack is just over one hour.
Run time using these same batteries is just over two hours.

NOTE: The included charger may only be used to charge the
included Ni-MH batteries or other AA Ni-MH batteries. NOT
Ni-CAD batteries.

Batteries that are warm or hot to the touch (from constant
usage or warm ambient temperatures) will take longer to
charge than batteries of a normal temperature. Contact BVS
for new Ni-MH battery packs. Expect over 500 cycles from
each Ni-MH pack.

GRASSHOPPER KEYPAD

Grasshopper uses a raised plastic keypad as its only inter­face. Below are simple descriptions of the buttons and their
features.

POWER - indicates if unit is On or OFF

RECEIVE - indicates if any signals are being received

LOW BATTERY - indicates low battery power warning

ESC - exits current menu screen

0 - adjust contrast screen

1 - activates Peak Hold mode (only in Spectrum Screen)

ENT - executes currently selected option

UP/DOWN ARROWS - scroll through selections

SETUP - enters the channel setup screen

CLR - clears current selection

GETTING STARTED

Operation of the Grasshopper is straightforward. Insert 5 fresh
battery cells into removable pack. Close the bottom back up
and power on the Grasshopper. The Grasshopper will instantly
display the screen to the right.

remove bottom cover

insert fresh batteries

Page 3

MAIN SCREEN

This is the main measurement screen used for monitoring and
selecting APs or Access Points. The window to the upper right
displays the received signal multipath in realtime of the cur­rently selected AP. Any AP listed under the AP Address window
is recognized as an IEEE 802.11b address. Multiple addresses
may be listed and monitored simultaneously here. Use the UP/
DOWN ARROW keys to toggle between all of these selections
and ENT to choose one.

Channel - indicates current channel selection for measure
Select AP - toggles between listed APs at bottom
Clear APs - clears list of APs shown at bottom
Scan for APs - scans all channels for authentic APs
Spectrum - enters spectrum analyzer mode

PER - indicates Packet Error Rate of current AP

The AP address window at the bottom indicates all IEEE
addresses indentified. The asterisk to the left indicates the
address that is currently selected.

dBm - indicates the signal strength of the last packet mea­sured.

W - indicates WEP (Wireless Equivalent Privacy). “P” indi­cates encryption is detected.

CHANNEL SCREEN

This selection opens the channel screen indicating all avail­able channels and their corresponding frequencies. Refer to
channel chart towards the end of this manual. Use the UP/
DOWN ARROW keys to toggle bewteen the desired channels
and the press ENT to choose the channel. The user may also
press SETUP on the keypad at anytime to access this screen.
Press ESC to exit screen.

multipath window

Page 4

SELECT AP

This selection places a cursor at the bottom of the screen to
the left of the AP addresses. By pushing ENT, the user selects
(indicated by an asterisk) a specific AP address to monitor.
Use Select AP to toggle through all received addresses. This
selection will change from Select AP to Select STA if the user
chooses to view all STA’s. See next menu option.

APs ONLY

This selection toggles between APs Only (valid Access Points
only) and all STAs Only (STAtions only or all DSSS channels
detected including valid APs). When the cursor is next to this
option, press ENT to toggle from one selection to the other.

SCAN FOR APs

This selection scans all 14 channels searching for authentic
access points. Up to 8 APs are listed. Pressing ENT will scan
again. Press ESC to exit to main screen. Note that only valid
APs can be scanned using this selection. STAs will not be
listed or scanned.

Page 5

SPECTRUM SCREEN

This RSSI screen indicates all received signals in a 22 MHz
bandwidth that Grasshopper continuously scans. Any peaks
indicate a signals although it could represent some spurious
noise so the user must check that their channel corresponds
with an appropriate AP address. The peak power is indicated
graphically and numerically on this screen as well as the
channel being scanned. Here, the signal peak indicates a nar­rowband jammer source. Press ESC to exit this screen.

RSSI SCREENS

The following screens illustrate various forms of interference
that Grasshopper’s Spectrum screen displays. The first screen
is a wideband 5 MHz jammer. Notice that the Peak Hold is Off
in the upper right corner.

narrowband jammer

PEAK HOLD

Peak Hold is only activated and deactivated in the Spectrum
Screen. Use Peak Hold when looking for interference sources
with low duty cycles. Push the 1 key on the keypad to turn ON
the Peak Hold. Push the 1 key again to turn the Peak Hold back
OFF. Remember the last signal displayed will reset when Peak
Hold is toggled ON.

wideband 5 MHz jammer

802.11 Access Point

Microwave Oven

Page 6

PER

This selection will display the Packet Error Rate screen for the
currently selected AP. The Rate column to the left indicates
the speed rate that is being used in Megabits per second. The
PER is based on actual packets coming in at different data
rates. PER indicates the Packet Error Rate using each of these
speeds in the selected AP. Usage displays the respective per­centage breakdowns between the 4 different transfer rates all
in the selected AP. PER is calculated by the percentage of bad
packets out of the packets coming in at that data rate.

PEAK

This screen provides various information and measurements
on the currently selected AP. Be sure to first select an Access
Point in the main screen and then select PEAK. The top line
displays the MAC address of the selected AP. Below that is
the current signal strength in dBm of the selected AP. Below
that is the PER of that AP. The bottom line displays the SSID
(Service Set IDentification). The small speaker icon to the
right of the screen indicates that the “geiger counter” mode is
enabled. This mode will sound a series of audible beeps that
indicate signal strength of the currently selected AP. Press the
number 8 key at anytime in this screen to toggle this mode ON
or OFF.

CONTRAST ADJUSTMENT

At anytime, press 0 on the key pad to access the Contrast
Adjustment screen. Use the UP/DOWN ARROW keys to
increase or decrease LCD contrast. When finished, press ESC
to exit this screen.

Page 7

BACKLIGHT ADJUSTMENT

At anytime, press CLR key to display the Grasshopper info
screen. Here, the current firmware version is displayed.
Press CLR again to toggle the backlght off and on. When
finished, press ESC to exit this screen. Remember that using
the Grasshopper without the backlight on will increase overall
battery life.

WEP ENCRYPTION DETECTION

A “P” next to its associated AP address and signal strength
indicates that WEP (Wireless Equivalent Privacy) encryption
is enabled and detected for that particular AP. An empty space
indicates no WEP.

UPDATING GRASSHOPPER FIRMWARE

1. Install the Grasshopper loader program on a PC. Insert Disk
1 of the Grasshopper loader and run Setup.exe. Install Shield
will guide you through the installation. Please make note of the
install directory. You will need this information later.

2. Connect the download cable to the Grasshopper and to the PC.
Turn the unit on and press the Setup key. This places the unit in
the channel selection screen.

3. Run the Grasshopper firmware loader installed in step 1.
Select the Comm port that the Grasshopper is connected to. Hit
the browse button and select the file that is located in the instal­lation directory for the Grasshopper firmware loader. Press the
load button and wait for the download to complete.

4. Turn the unit off. In order to reset the unit and run the new
firmware, turn the unit off, remove the download cable and turn
the unit back on.

WEP Encryption

The Grasshopper firmware loader can be uninstalled from your
computer at this point.

Page 8

Networking Basics

Packets and traffic
Information travels across a network in chunks called “packets.” Each packet has a header that tells where
the packet is from and where it’s going, similar to what you write on the envelope when you send a letter.
The flow of all these packets on the network is called “traffic.”

Hardware addresses
Your PC “listens” to all of the traffic on its local network and selects the packets that belong to it by check­ing for its hardware address in the packet header or MAC (Media Access Control). Every hardware product
used for networking is required to have a unique hardware address permanently embedded in it.

IP addresses
Since the Internet is a network of networks (connecting millions of computers), hardware addresses alone
are not enough to deliver information on the Internet. It would be impossible for your computer to find its
packets in all the world’s network traffic, and impossible for the Internet to move all traffic to every net­work, your PC also has an IP (Internet Protocol) address that defines exactly where and in what network
it’s located. IP addresses ensure that your local Ethernet network only
receives the traffic intended for it. Like the hierarchical system used to define zip codes, street names,
and street numbers, IP addresses are created according to a set of rules, and their assignment is carefully
administered.

Put another way, the hardware address is like your name; it uniquely and permanently identifies you. But it
doesn’t offer any clues about your location, so it’s only helpful in a local setting. An IP address is like your
street address, which contains the information that helps letters and packages find your house.

Rules for Sending Information (Protocols)
A protocol is a set of rules that define how communication takes place. For instance, a networking proto­col may define how information is formatted and addressed, just as there’s a standard way to address an
envelope when you send a letter.

Networking Devices:
Bridges
A bridge joins two networks at the hardware level. This means that as far as other protocols are concerned,
the two networks are the same.

Routers
A router connects two IP networks. In contrast to a bridge, which joins networks at the hardware level, a
router directs network IP traffic based on information stored in its routing tables. A routing table matches
IP addresses with hardware addresses. The router stamps each incoming IP packet with the hardware
address that corresponds to that IP address. As a result, the packet can be picked up by the right computer
on the hardware network.

DNS (Domain Name Server)
Networks (domains) on the Internet have names that correspond to their IP addresses. A Domain Name
Server maintains a list of domain names and their corresponding addresses. This is why you can go to
Berkeley’s Web site by entering www.bvsystems.com, instead of the IP address.

Networking Terms:

Page 9

TCP/IP (Transport Control Protocol/Internet Protocol)
TCP/IP is a collection of protocols that underlies almost every form of communication on the Internet.
DHCP (Dynamic Host Control Protocol)
DHCP is a method of automatically assigning IP addresses. Instead of assigning addresses to individual
users, addresses are assigned by the DHCP server when clients need them. This means that instead of
entering several fields of long addresses, users need only to select DHCP as their configuration method
for IP networking.
PPP (Point-to-Point Protocol)
PPP is the most common protocol for providing IP services over a modem.
NAT (Network Address Translation)
NAT is used to share one IP address among several computers. A device set up as a NAT router uses a col­lection of “private” IP addresses (in the range 10.0.1.2 to 10.0.1.254 for example) to allow several com­puters to access the Internet using one “public” IP address. When a computer using a private IP address
requests information from the Internet, the NAT router keeps a record of the computer making the request,
and sends the information to the Internet using its own IP address. When the response comes back from
the Internet, the NAT router forwards the packet to the appropriate computer.

Channel Frequency North Europe Spain France Japan
Number GHz America MKK

1 2.412 X X
2 2.417 X X
3 2.422 X X
4 2.427 X X
5 2.432 X X
6 2.437 X X
7 2.442 X X
8 2.447 X X
9 2.452 X X
10 2.457 X X X X
11 2.462 X X X X
12 2.467 X X
13 2.472 X X
14 2.483 X

DSSS INTERNATIONAL CHANNEL CHART

Page 10

Glossary of Acronyms

AC Alternating Current
A/D Analog to Digital converter
AGC Automatic Gain Control
AP Access Point
Applet a small Application
BER Bit Error Rate
BPSK Binary Phase Shift Keying
BSS Basic Service Set
BW Band Width
CDMA Code Division Multiple Access (spread spectrum modulation)
DC Direct Current
D/A Digital to Analog
dB decibel
dBm decibels referenced to 1 milliwatt
DOS Digital Operating System
DSP Digital Signal Processing
DSSS Direct Sequence Spread Spectrum
ESS Extended Service Set
FIR Finite Impulse Response
GHz GigaHertz
IF Intermediate Frequency
I and Q In phase and Quadrature
IBBS Independent Basic Service Set
kHz kiloHertz
LCD Liquid Crystal Display
LO Local Oscillator
MAC Medium Access Control
Mbits Megabits
MHz MegaHertz
NIC Network Interface Card
OFDM Orthogonal Frequency Domain Multiplexing (802.11a)
PC Personal Computer
PCS Personal Communications Service (1.8 to 2.1 GHz frequency band)
PER Packet Error Rate
PN Pseudo Noise
QPSK Quaternary Phase Shift Keying, 4-level PSK
RF Radio Frequency
RSSI Receiver Signal Strength Indicator
SSID Service Set IDentification
UCT Universal Coordinated Time
VAC Volts Alternating Current
VGA Video graphic
WEP Wired Equivalent Protocol
WLAN Wireless Local Area Network

Page 11

IMPORTANT SAFETY INSTRUCTIONS

When using your telephone equipment, basic safety precautions should always be followed to reduce the risk of fire, electric
shock and injury to persons, including the following:

1)Read and understand all instructions.

2)Follow all warnings and instructions marked on the product.

3)Unplug this product from the wall outlet before cleaning. Do not use liquid cleaners or aerosol cleaners. Use a damp cloth
for cleaning.

4)Do not use this product near water, for example, near a bath tub, wash bowl, kitchen sink, or laundry tub, in a wet basement,
or near a swimming pool.

5)Do not place this product on an unstable cart, stand, or table. The product may fall, causing serious damage to the product.

6)Slots and openings in the cabinet and the back or bottom are provided for ventilation, to protect it from overheating these
openings must not be blocked or covered The openings should never be blocked by placing the product on the bed, sofa, rug or
other similar surface. This product should never be placed near or over a radiator or heat register. This product should not be
placed in a built-in installation unless proper ventilation is provided.

7) This product should be operated only from the type of power source indicated on the appliance. If you are not sure of the type
of power supply to your home, consult your dealer or local power company.

8)Do not allow anything to rest on the power cord. Do not locate this product where the cord will be abused by persons walking
on it.

9)Do not overload wall outlets and extension cords as this can result in the risk of fire or electric shock.

10)Never push objects of any kind into this product through cabinet slots as they may touch dangerous voltage points or short
out parts that could result in a risk of fire or electric shock. Never spill liquid of any kind on the product.

11) To reduce the risk of electric shock, do not disassemble this product, but take it to a qualified service faciI4 when some
service or repair work is required. Opening or removing covers may expose you to dangerous voltages or other risks. Incorrect
reassembly can cause electric shock when the appliance is subsequently used.

12)Unplug this product from the wall outlet and refer servicing to qualified service personnel under the following conditions:

A) When the power supply cord or plug is damaged or frayed. B) If liquid has been spilled into the product.

C)If the product has been exposed to rain or water.

D) If the product does not operate normally by following the operating instructions. Adjust only those controls, that are
covered by the operating instructions because improper adjustment of other controls may result in damage and will often require
extensive work by a qualified technician to restore the product to normal operation.

E) If the product has been dropped or the cabinet has been damaged. F) If the product exhibits a distinct change in perfor­mance.

13)Avoid using the product during an electrical storm. There may be a remote risk of electric shock from lightning.

14)Do not use the telephone to report a gas leak in the vicinity of the leak.

INSTALLATION INSTRUCTIONS

1. Never install telephone wiring during a lightning storm.

2. Never install telephone jacks in wet locations unless the jack is specifically designed for wet locations.

3. Never touch uninsulated telephone wires or terminals unless the telephone line has been disconnected at the network inter­face.

4. Use caution when installing or modifying telephone lines.

INSTRUCTION FOR BATTERIES

CAUTION: To Reduce the Risk of Fire or Injury to Persons, Read and Follow these Instructions:

1. Use only the type and size of batteries mentioned in owner’s manual.

2. Do not dispose of the batteries in a fire. The cells may explode. Check with local codes for possible special disposal
instructions.

3. Do not open or mutilate the batteries. Released electrolyte is corrosive and may cause damage to the eyes or skin. It
may be toxic if swallowed.

4. Exercise care in handling batteries in order not to short the battery with conducting materials such as rings, bracelets,
and keys. The battery or conductor may overheat and cause burns.

5. Do not attempt to recharge the batteries provided with or identified for use with this product. The batteries may leak
corrosive electrolyte or explode.

6. Do not attempt to rejuvenate the batteries provided with or identified for use with this product by heating them. Sudden
release of the battery electrolyte may occur causing burns or irritation to eyes or skin.

7. When replacing batteries, all batteries should be replaced at the same time. Mixing fresh and discharged batteries
could increase internal cell pressure and rupture the discharged batteries. (Applies to products employing more than one sepa­rately replaceable primary battery.)

8. When inserting batteries into this product, the proper polarity or direction must be observed. Reverse insertion of bat­teries can cause charging, and that may result in leakage or explosion. (Applies to product employing more than one separately
replaceable primary battery.)

9. Remove the batteries from this product if the product will not be used for a long period of time (several months or more)
since during this time the battery could leak in the product.

10. Discard “dead” batteries as soon as possible since “dead” batteries are more likely to leak in a product.

11. Do not store this product, or the batteries provided with or identified for use with this product, in high-temperature
areas. Batteries that are stored in a freezer or refrigerator for the purpose of extending shelf life should be protected from con-

densation during storage and defrosting. Batteries should be stabilized at room temperature prior to use after cold storage.

Below are Radiation Patterns for the included N2400SMA1G Antenna (left) and BVS’ optional
DF corner reflector (right). The Antenna Under Test was measured against a 1/2 Wave
Dipole, therefore; The Gain is measured in dBd (0 dBd = 2.14 dBi).

IEEE 802.11 TESTER

The Grasshopper is just one of many exceptional
design solutions from Berkeley Varitronics.
Call us today for more information:

[phone] / Fax: [phone]

Internet: www.bvsystems.com
E-mail: [e-mail]

FEATURES:

• Measure coverage for direct sequence (DSSS) wireless networks (wideband IF 22 MHz)

• Tests 2.4 GHz DSSS networks operating within the IEEE 802.11b standard

• Measures Packet Error Rate

• Measures and displays channel time dispersion for multipath analysis

• Measures and displays RF power measurements: narrow band received signal strength (RSSI),

total channel power

• Light-weight, portable and rugged design ideal for realtime network analysis

• Removable battery pack (5 AA Ni-MH cells)

• Built-in numeric keypad, backlit display with simple menu interface

Grasshopper

WLAN 2.4 GHz SCANNER

TM

BERKELEY

VARITRONICS

SYSTEMS

wireless products

Grasshopper™ is a
handheld, wireless
receiver designed
specifically for sweep­ing and optimizing
Local Area Networks.
The instrument mea­sures coverage of
direct sequence CDMA
networks which oper­ate on the IEEE 802.11b
standard allowing the
user to measure and
determine the AP
(Access Point), PER
(Packet Error Rate),
and RSSI signal levels

aiding in locating the
hub and access points throughout a building. Grasshopper™ detects and differentiates from narrow­band multipath interferences such as microwave ovens and frequency hopping systems and fea­tures a built-in display, keypad and removable battery pack for true portability.

Apple’s Airport Basestation and Nokia’s Access Point LAN are shown above and are the registered trademarks of Apple Computer and Nokia respectively.

BANDS SUPPORTED ISM: 2.400-2.485 GHz
RF SENSITIVITY (Wide Band) -20 to -90 dBm
RSSI MEASUREMENT (Narrow Band) -30 to -90 dBm @ 100 kHz resolution bandwidth
TUNING INCREMENTS 50 kHz steps

PACKET PREAMBLE DEMODULATOR and ANALYZER:

Multipath Measurement and Graphical Display

CORRELATED POWER MEASUREMENTS: RATIO

Correlated Power (dBm) -30 dBm : -100 dBm
Correlated Power to Total Power Ec/Io (dB) 0 dB : -10 dB
Total Channel Power Measurement -20 dBm : -90 dBm

GENERAL SPECIFICATIONS

IF Bandwidth: Wideband 22 MHz

Stability: + 2.5 PPM Temp range 32° to 120 F°

Antenna: SMA Female 50 ohm
Controls: 20 button keypad

Warm Up Time:

< 3 minutes

Power: Internal battery pack (5 AA Ni-MH batteries)
Weight: 3 lbs.

Dimensions: 2” H x 4” W x 9” L (water resistant, high impact ABS plastic case)

Berkeley Varitronics Systems, Liberty Corporate Park, 255 Liberty Street, Metuchen, NJ 08840

Phone [phone] • Fax [phone] • Internet: www.bvsystems.com • E-mail: [e-mail]

WLAN 2.4 GHz SCANNER

IEEE 802.11 TESTER

Grasshopper

TM

*Multipath and signal quality assessment via comparison of correlated power to total

channel power ratio and correlated power.

*Features graphical display of multipaths.

*Interference detection via RSSI scan and active DSSS 802.11 channel scan.

Grasshopper includes a straight 3dBi 2.4 GHz
antenna (SMA Female 50 ohm), two remov­able battery packs (5 AA Ni-MH cells each)
charger,
RS-232
cable
all in a
rugged
carry­ing case.