The node hardware specifics
Each of our nodes (device sets) is comprised of the following hardware
-- Soekris net4826/5501 board and case: The Soekris
to two mini-PCI cards. Most of our boxes contain two wireless miniPCI
cards; an Atheros EMP 8602, and a Ralink RT2860 MIMO card.
We use Power-over-Ethernet (PoE) throughout the testbed. With PoE, we are able
to control the power supply to each node, through a managed,
PoE-enabled switch. More details for the specs of this
communication computer can be found in the Soekris
Engineering web page. The specifications that we are mainly
interested in, are the following:
233/266 Mhz AMD Geode
32-256 Mbyte SDRAM soldered on board
10/100 Mbit Ethernet port
2 Mini-PCI type III sockets
Power using external power supply is 11-56V DC, 12W
Be careful: We have not
managed to power the board directly from the Ethernet port; so make
sure you can do this. Otherwise you need the D-Link-P50 PoE adapter,
that we explain below.
-- ETTUS USRP GNU radio: The Universal Software Radio
Peripheral, or USRP, is a device which allows you to create a software
radio using any computer with a USB 2 port. Various plug-on
daughterboards allow the USRP to be used on different radio frequency
bands. Daughterboards are available from DC to 2.9 GHz at this time.
The entire design of the USRP is open source.
USRP GNU radio
12-bit 64M sample/sec
4 14-bit, 128M sample/sec DACs
Programmable USB 2.0 controller
-- WARP board: WARP is a scalable and
extensible programmable wireless platform, built from the ground up, to
prototype advanced wireless networks. ARP opens both hardware and
software needed to research, build and prototype next-generation of
wireless networks. This is enabling a community of researchers to pool
their ideas in undertaking clean-slate prototype networks.
Xilinx Virtex-II Pro
-- DELL Inspiron 530S: This is regular Dell
machine that is used to connect and manage the GNU radios and the WARP cards.
DELL Inspiron 530S
250 GB hard disk
1 GB RAM
-- Linksys EZXS55W
5-port switch: We use this small, efficient switch to connect
the devices within a device set.
per-port auto sensing
Up to 200 Mbps in full-duplex operation
-- D-Link DWL-P50 PoE adapter:
This is an
external PoE splitter, used to isolate the power from the PoE supply,
and forward it to a specific output, toward the net4826 board. We use
this item in order to be able to remotely power on/off the Soekris
boxes, without affecting the rest of the devices in a device set. This
is clearly seen at a later figure that shows the device connectivity
within a device set. The cool feature with this device is that even
when there is no PoE enabled, the data is still travelling from the
input to the output port of the device. Hence, when we decide to power
off a Soekris node, the rest of the devices can still exchange data
with the server and the rest of the network!
Power over Ethernet
-- EMP-8602 6G miniPCI WiFi card: We are using
this high-power wireless mini PCI card for the node's wireless
interface. Using the latest in technology expertise, the EMP-8602 / NMP-8602 mini-PCI is the longest range
and most powerful RF module on the market today.
EMP-8602 6G IEEE
* 26 dBm +/- 2dBm
* 26 dBm +/- 2dBm 802.11g
* 20 dBm +/- 2dBm 802.11a
Supports the MadWifi
driver for linux
U.FL antenna connectors
Input Voltage: 3.3V
-- Ralink RT2860 miniPCI WiFi card: This is also a power Wifi
card, which use mainly use for MIMO experiments and implementations. It
has three inputs for antennas, therefore we had to drill our boxes to
host the antennas. We thank Ralink Corp. for providing the Linux
drivers for access points and clients.
Chipset: Ralink RT2860
Mini PCI Type IIIB
Backward Compatible with 802.11b/g
-- Intel 2915abg mini PCI WiFi card: The Intel 2915 wireless cards use the flexible
open-source ipw2200 Linux driver. This solution is based on the MiniPCI
Type 3B form factor. We thank Intel Research for donating 29 cards and for
providing the prototype Linux drivers for access points and clients.
INTEL 2915 IEEE
U.FL antenna connectors
ipw2200 Intel driver, firmware
WEP - 128-bit,
WEP - 64-bit,
Weight 0.46 oz
-- U.FL to Rp-SMA Pigtail: We use this pigtail to connect the wireless card with the
external antenna of the node.
U.FL to RP-SMA
7.9'' overall length
1.13 mm cable
-- RD2458-5-RSMA Rubber Duck Antenna: This is a
triBand APXtender indoor rubber duck antenna with RSMA male connector. We are quite
happy with its capabilities, so far.
RSMA male connector
The following picture shows an assembled Soekris node, with
Atheros card only, without its cover:
In order to be able to manage the nodes centrally and initiate
experiments, we use a server, which is located in our laboratory. The
server is a DELL Pentium IV at 1.8 GHz, with 768 MB or memory. The
server is equipped with two Ethernet cards. One is used for the testbed
VLAN connectivity, and the other for the connectivity to the outer
world. The nodes are remotely accessible only through the server.
DELL P4 @ 1.8 GHz
2 10/100 Mbit Ethernet
768 MB SDRam
1 Serial port
The server's hostname is "dux".
Besides the server, we also use a desktop PC for building software and
kernels. This Pentium III desktop PC runs the same operating system
with the nodes. We use this PIII PC to compile drivers, kernels and
applications used by the nodes. Moreover, for our initial experiments
we purchaced a MICROTEL desktop PC for various testing procedures. (We
are not using that anymore).
We use a set of D-Link - DES-1526 - 24-Port 10/100 Web Smart
Switches. The purpose of these PoE switches is twofold. First, they
connect each node to the server's Ethernet interface. This is for being
able to remotely access the nodes. Second, they provide power to the
nodes. In that way we are able to remotely power on/off the nodes, by
enabling/disabling power support of the corresponding ports of the PoE
switches. The software method is provided in our tools page.
D-Link - DES-1526
2 combo 1000Base-T/SFP
8.8G Switching Capacity
64 802.1Q VLAN Groups
802.3ad Link Aggregation
24 Port 802.3af PoE
BootP / DHCP Client
Each switch features 24 PoE 802.3af ports integrated into a
Web-Smart switch. It has advanced features such as SNMP, VLANs,
priority queuing, and port monitoring/statistics. It provides up to
15.4Watts of power injection per PoE port. BootP and DHCP are protocols
used to send configuration information to a client such as an IP
address, subnet mask, and default gateway. The DES-1526 supports these
protocols as a client and is capable of receiving this important
configuration automatically without having to be manually configured by
a network administrator. Currently we are using 2 switches.
Installing a PoE switch is not a difficult task. the most
difficult part is to get authorization to access the network closet.
The switch will be install in the same closet as the department's
switches. As soon as the corresponding ports are connected, the
installation is finished. The switches that we have so far are equipped
with a web interface. In order to access it, one has to connect a
machine to the testbed network, and use a web client. The web interface
provides very useful information, such as e.g. which ports are enabled,
and how much power each port consumes. Moreover, through the web
interface one can set the IP of the switch.
By default the switch's IP is 192.168.0.1. In order to
change this, one has to connect a machine to the testbed, and set the
IP of this machine to be the latter one. Further one can change the IP
of the switch to the preferable one. There may be times where the IP of
the switch is automatically set to be the default one - 192.168.0.1
(e.g. perhaps after a power outage). You need to follow the above
steps, in order to change it again. This is of course necessary only if
you care contacting the switch now and then (e.g. in order to reboot
From the description of the nodes, the server and the
switches, it is easy for one to understand how a node is connected to
the server. This is depicted in the figure below.
The switches have been installed in the department's network
closets, together with the department's switches. These network closets
- rooms can communicate vertically between floors, but not within the
same floor. As an example, the 3rd and 4th floor network closets in the
faculty wing of the building can communicate with regular network
cabling. However, the two network closets in the 3rd floor cannot
communicate with regular network cabling. Luckily for us, there is
connectivity through fiber optics. As a consequence, in order to
connect two of our swiches that are placed in the 3rd floor (in the two
isolated network closets), we need Ethernet to Fiber converters.
For this, we use two CVT-100BTFC(SM-30) Media Converters, one for each
switch. These converters are fully compliant with the IEEE 802.3 and
802.3u Fast Ethernet standards and feature one STP-RJ45 10/100Base-TX
port as well as one Fiber Optic 100Base-FX SC port. Each unit is
powered by an external power supply. Installation of the Fast Ethernet
converter is simple and straightforward.
Auto cross over for TP port
Support Link Alarm
Support Switch mode & Pure converter mode
Dual Port 10/100Mbps Switch inside
The cabling that we use for the testbed
involves mainly cat-6 patch network cables. For convenience, we use 7ft
black cables in the network closets. The cat-6 patch cables that we use
to install nodes in rooms do not have a specific color or length.
Also, for connecting the switches we use
Single Mode SC Duplex Cables.