Nomadic Communications - aa 2015-16

Questo spazio è dedicato alle comunicazioni di servizio, e mantiene quindi anche la storia delle variazioni del corso. È una buona idea dare un'occhiata al sito prima di ogni lezione sia per trovare eventuali novità che per verificare il materiale didattico distribuito.

• Monday May 23:The slides on Vehicular Networks are available. Today there is no theory lesson. The last seminar on Wireless Mesh and Community Networks will be Monday May 30.
• Monday May 2: Today we finish the main topic of the course. In the remaining three theoric lessons we will have very interesting seminars on Vehicular and Community Networks: don't miss them ... they are in any case part of the exam program!
• Monday Feb. 15, 15:30: The first version with slides is on-line.
• Monday Feb. 15: There has been a delay in setting up the site, I'm sorry, my responsibility .... things will change in the next hours, stay tuned!

We begin the course with a rush on theory, in order to have enough knowledge of Wireless Networks, WIFI and 802.11 standard and systems before we start the Labs. This means that weeks 2 and 3 we have 4 hours of theory as follows:

• Monday Feb. 22, 9:00-11:00 room A107
• Monday Feb. 22, 14:00-16:00 Networking Teaching Labs at level -2 in Povo 2; to be confirmed
• Monday Feb. 29, 9:00-11:00 room A107
• Monday Feb. 29, 14:00-16:00 Networking Teaching Labs at level -2 in Povo 2; to be confirmed

March 7 we start the regular calendar

• Theory: Mondays 9:00-11:00 room A107
• Labs
  • Mondays 14:00-18:00, Networking Teaching Labs at level -2 in Povo 2.
    These are the "official hours" in calendar for the lab. Francesco Gringoli will normally be present, will explain the laboratory topic, help you setup experiments and answer all questions. I will also be there sometimes.
  • Wednesdays 14:00-18:00, Networking Teaching Labs at level -2 in Povo 2.
    The lab is reserved for you to complete experiments, play with devices, start writing reports. Me or Francesco may drop-by from time to time, but our presence is not guaranteed. You will have to take the lab keys and responsibility on the devices.

The formal exams dates during the summer will be defined later during the course.

You have to subscribe via ESSE3 when you want to take the exam, however the actual date of the exam is free, you just have to take an appointment with me. I strongly encourage groups to take the oral together, but there is no fromal requirement on this.

The oral can be taken when the lab reports are delivered in their final form, but you have to allow me 3-4 days minimum to correct the reports.

This year the labs are centered on actual impementation and design of MAC protocols on embedded Linux devices featuring the OpenFWWF platform.

OpenFWWF is a reverse-engineered platform that provides an easy and inexpensive platform to implement new Medium Access Control (MAC) mechanisms and protocols, and is a valid alternative to simulations and expensive ad-hoc platforms. The combination of OpenFWWF and b43 driver is a complete and cheap tool that makes testing of new MAC easy achievable, which let us run true lab work on nomadic systems and appreciate differences between design chioces and various options in wireless protocol design.

Labs are best done in groups. Groups of three are the best, but two or even singles can be accepted. More than three the work bocomes too dispersive.

Here is a template and LaTeX style to write decent reports, with some hints on the organization.

We don't have any "official textbook." Here are the printouts of the slides I use to follow a predefined course while teaching. They are by no means a textbook and I will spend maybe half a lesson on a single slide and ... surf over the next 10 in 10 minutes. They are intended to help you in scribbling notes, not to substitute the lessons. They are normally posted before the lesson, but sometimes they are modified to improve them also after discussion in class, in this case they are marked with the date of the modification. If you want to have an idea of the whole material you can check the material of the past years, but I normally change part of the course, so do not entirely rely on old material.

• Introduction, general notions and rehearsal of known concepts: MAC protocols and protocol architectures.
  • PDF - slides
• 802.11: The WLAN standard. Generalities, the base access protocol and the different PHY layers.
  • Fundamentals of the MAC protocol PDF - slides
  • Fundamentals PLPC and PHY layers PDF - slides
• 802.11e: Changing the MAC to enchance fairness and performance, and differentiate services.
  • PDF - slides
• 802.11n/ac: Using Space diversity to enchance capacity and resilience.
  • PDF - slides
  • Cisco whitepaper introducing its own 802.11ac products, obviously biased, but with interesting details and comparisons
• Vehicular Networks by Michele Segata
  • PDF - slides

The 802.11 standard and related documents are available for free download (but you need to register) from the IEEE 802.11 website It includes all parts of the standard including MACs and PHYs definitions: 802.11b/g/a/h/n; 802.11e and much more. You can consider it the ultimate source of information, but it is unfortunately a bit hard to read and ... it is 2793 pages! Use it to check values of parameters or to determine the exact meaning of fields etc. Chapter 8 and 18 are suggested reading as Gringoli said in the lab presentation.

All the lab material produced by Francesco Gringoli is available through this page he hosts. Most of the material is also mirrored in the list below, but check the original site if you have doubts on updates and similar stuff

• Introduction
• Course notes
• Introduction to IEEE 802.11
• Linux Networking Kernel Stack
• OpenFWWF: receive and transmit code paths
• Laboratory tutorials
• Network setup and performance measurement
• Basic exercises with the firmware: receive path explained

Official WebSite of OpenFWWF