Technology - Expert Notes
Ellisys Expert Notes are quick technical notes illuminating some difficult
specifications aspects. Each Expert Note include a main document and optional
attachments such as traces, scripts, etc.
Bluetooth BR/EDR and Low Energy
 |
EEN_BT01 - Capturing Bluetooth Traffic, the Right
Way |
| |
Bluetooth is a difficult technology to sniff. Advanced communication
techniques such as frequency hopping, whitening, and encryption are all
characteristics that make this ever-evolving technology “sniffer
unfriendly”. This paper covers how these challenges affect engineers
and what we can do to improve the situation. We will specifically cover
wireless capture, focusing on the two sniffing techniques available today:
single-channel sniffing and whole-band concurrent channel sniffing. |
 |
EEN_BT03 - Your First Wide-band Capture |
| |
A wide-band sniffer is very easy to use. Start the capture, connect
your devices and all traffic will immediately be captured. There are
a few things that need to be known however, in order to get a perfect
capture. This document guides the reader through some simple steps
required to ensure an optimal capture. |
 |
EEN_BT04 - Optimal Placement of Your Analyzer |
| |
Capturing Bluetooth traffic with a whole-band sniffer is a
piece of cake: just turn on your analyzer, start capturing and your traffic
is displayed right away. However, as with any wireless technology, some
care must be taken to ensure that the analyzer is placed in an ideal
position in order to robustly capture the traffic. This paper provides
some good practices and explains a few pitfalls to be avoided.
|
 |
EEN_BT05 - Understanding Antenna's Radiation
Pattern |
| |
A basic understanding of antenna radiation patterns is very useful
for correctly positioning your wireless devices, in order to ensure the
most ideal transmission quality. This is even more important when doing
protocol analyzer captures. This document provides some basic information
about radiation patterns of various antenna types. |
 |
EEN_BT06 - Bluetooth Security - Truths and
Fiction |
| |
Bluetooth security is a complex and often-misunderstood topic.
A good understanding of security principles is important, but it is equally
important to understand how protocol analyzers handle security in order
to correctly define security requirements in a Bluetooth device.
This paper covers a few often-misunderstood topics and will provide
clarifications.
|
 |
EEN_BT07 - Secure Simple Pairing Explained |
| |
Stronger security introduced by SSP means new challenges for Bluetooth engineers.
Debugging off-the-shelf devices in the field becomes difficult to impossible.
Things are not as bad as they may seem however. This document introduces
the basics of SSP and clears up some misconceptions commonly found
in the Bluetooth community.
|
 |
EEN_BT08 - Separating the Wheat from the Chaff |
| |
Bluetooth topologies are becoming increasingly complex as the
technology evolves and new, more sophisticated applications begin to
appear. Busy lab environments or public testing events (like UPFs) can
involve dozens or even hundreds of devices, all active at the same time.
This paper will walk the user through the process of using the powerful Device
Traffic Filter and associated Device Database, and will touch
on usage applications for other filter mechanisms.
|
SuperSpeed USB 3.0
 |
EEN_SS01 - Link Layer and Protocol Layer Retransmission
Mechanisms |
| |
USB 3.0 retransmission mechanisms are quite different from USB 2.0
because of the new routing infrastructure. USB 3.0 has separate retransmission
mechanisms in the Link and the Protocol Layers for optimizing data buffering
in devices and especially hubs. We will examine in this document the
traffic exchanged between two link partners (such as a host and a device)
when a DPH is received as invalid by one end. |
| |
Attachments: trace | script |
|