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--- activities [2017/10/26 10:20]
mustafaelnainay
+++ activities [2017/10/26 10:28] (current)
mustafaelnainay
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 stages of the project.
+----
 ==== CRC Hardware ====
 === Nodes ===
@@ Line 51: / Line 52: @@
 exposure to the newly learned concepts.
+----
 ==== CRC Software ====
@@ Line 88: / Line 90: @@
-===== Building small scale ORBIT testbed replica using ORBIT software modules =====
+===== CRC Phase I Novel Features =====
+==== Isolated Multiple Concurrent Users ====
+One of the new features in CRC is its ability to have multiple concurrent users access its resources while
+guaranteeing no interference. Other testbeds, e.g. [[http://www.orbit-lab.org/|ORBIT]], give exclusive access to a group of their nodes to a single user regardless of his needs. NITOS enables simultaneous users but relies on the
+integrity of users to commit to their reserved frequencies. To be capable to accommodate concurrent
+users two challenges exist: the first is limiting each user to his reserved nodes and preventing him from
+unauthorized access either by mistake or deliberately. The second challenge is to enforce frequency
+assignments. As the wireless medium, unlike wired, is of broadcast nature, two users conducting
+experiments on the same frequency can compromise the integrity of each other’s work. Thus, ensuring
+that users work on their allocated band is important. NITOS handles only the first challenge. CRC, on
+the other hand, handles both challenges, making it truly support concurrent experimentation by different
+users.
-==== Short Description ====
+==== Enforcing Frequency Assignment ====
+Each user while reserving nodes is required to reserve frequencies. Confining each user to his reserved
+spectrum can be done by monitoring for frequency violations. Once a violation is detected, the offending
+user can be forced out of the testbed and perhaps have his account suspended. The approach we took
+at CRC to detect such violations is a software based approach.
+Three wireless interfaces exist currently at CRC; USRP, RTL-SDR, and WiFi. The RTL-SDR is a
+receiver only, so, it does not cause interference. The WiFi standard enables multiple users to share
+the same channel and monitoring its frequency usage can be performed through the operating system.
+This makes the major source for interference is the USRP, which will be our focus when dealing with
+frequency isolation. The USRP available at CRC communicates with the virtual machines through USB
+using packets with a predefined structure. By sniffing these packets from the physical nodes, we can
+tell what frequency band is being used and hence detect violations.
-==== Resources ====
+==== Testbed Nodes Virtualization ====
-[[https://drive.google.com/open?id=0B0-0d_WzArTUZHQ2RDIweDRjNW8&authuser=0]]
+Virtualization of nodes is common in wired testbeds and has been used to extend the scale of experiments
+in wired networks, e.g. in [[https://www.emulab.net/|Emulab]]. None of the existing wireless testbeds uses node virtualization.
+The smallest unit to be reserved in these testbeds is the physical node. This is explained by
+the following; in wired networks, virtualization of network resources like interfaces and links is possible
+without jeopardizing integrity of results due to the controlled nature of wires. In wireless communication,
+although some work has been done on the virtualization of WiFi, reliable virtualization of SDR
+peripherals, which are physical layer devices, is difficult. At CRC, testbed nodes are virtualized based
+on interfaces; each physical node runs three virtual machines and each virtual machine is assigned one of the three interfaces. Hence, this setup allows multiple simultaneous users, who need different
+interfaces, to use the same physical machine.
+==== Topology Control using Gains ====
+Some wireless experiments depend on the existence of a specified topology between the nodes. For
+example, some cognitive radio scenarios require certain connectivity between the nodes. Changing the
+transmitter power and the amplification at the receiver by changing the transmit and receive gains of
+the nodes can be used to realize a given topology. Selecting suitable nodes and finding suitable values
+for the gains using trial and error is a time consuming process. In CRC, we developed a system, that
+given a desired topology, will find values of the transmit and receive gains for the nodes to achieve the
+desired topology.
-----
+==== Storage Efficient Disk Imaging System ====
+The users’ images are always derived from the base image provided by the administrators of CRC
+which is stored on the server. Users may perform some changes on the image and then save it back
+to the storage server using [[https://www.cs.utah.edu/flux/papers/frisbee-usenix03-base.html|Frisbee]]. The drawback of Frisbee is that it stores the entire disk image
+which leads to having duplicate data. To avoid this, we use a proven data duplication software which
+is [[https://www.usenix.org/legacy/events/fast02/quinlan/quinlan_html/|Venti archival storage system]]. Venti is a block level storage system, it identifies duplicate blocks
+and avoids data duplication. Our work was on the integration of Venti and Frisbee to get the benefits of
+both; Venti avoids duplication, while Frisbee enables fast and scalable image transfer.
-===== Studying the Software Defined Networking and possibilities to integrate into CRC testbed =====
-==== Short Description ====
-A document describing how to include SDN in the CRC testbed and possible research directions.
-==== Team ====
-==== Resources ====
-[[https://drive.google.com/open?id=0B0-0d_WzArTUQnpCcDRaQUNMb2M&authuser=0]]
 ----
-===== Survey portals of other testbeds and plan CRC portal =====
-==== Short Description ====
-==== Team ====
-==== Resources ====
-----
-===== Study the interference model of the SmartCI research building =====
-==== Short Description ====
-==== Team ====
-==== Resources ====
-----
-===== Study the suitable testbed nodes positions inside the research building =====
-==== Short Description ====
-==== Team ====
-==== Resources ====
-----
-===== How to use flack in GENI experimentation  =====
-==== Short Description ====
-An introductory presentation to the GENI testbed, and how to use the flack software in setting an experiment
-==== Team ====
-==== Resources ====
-About GENI testbed
-https://drive.google.com/open?id=0B5q_HJKGbI38aDZCaFJNOC1MZnM&authuser=1
-Using Flack
-https://drive.google.com/open?id=0B5q_HJKGbI38TGtiWmM5UWN1Z0k&authuser=1

CRC: Communication and Networking Testbed

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