By Michayla Newcombe - September 8, 2014
The UNH-IOL’s Women in Technology (WIT) group was pleased to hold their first event here at the UNH-IOL on Wednesday, August 27th. WIT is a recently formed group at the lab that I have the pleasure of serving as a co-chair along with Marion Dillon, Home Networking Manager, Home Networking Technologies. The event, titled “Women in Industry”, featured four women panelist, all of whom work in tech related industry jobs. Before I get too far, here is a little background about the WIT group at the lab. WIT was formed to represent and provide support for women who work in the tech field (including the ladies at our own lab). We hope to to attract females to STEM degrees as well as the lab. We want the lab to be an open place where everyone feels welcome and supported.
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Tags: Women In Technology, Education, STEM
By Nick Piscitello - August 4, 2014
When I walked in on Monday to start working, I had absolutely no idea what to expect. I did know the basics – the IOL is a network interoperability testing facility, staffed by mostly college students and funded through contracts with third party vendors. I knew this place saw its share of brand new, highly confidential products, and that the IOL is very unique – the only test lab of its kind in the world, in fact, according to the website. I knew that I would be working on building an IPv6/SDN demo with Intel’s Galileo board, and I knew approximately how to go about that. I considered myself prepared to dive right in.
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By Jackson Corson - July 11, 2014
Packet aggregation is the idea of creating packet fragmentation which reduces time on a busy WM and makes error recovery much easier. 802.11e was the first standard to outline a different form of packet aggregation known as A-MPDU (Aggregated MAC Protocol Data Unit). MPDU is what we know as an 802.11 packet, making A-MPDU per packet aggregation.
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By Jackson Corson - June 30, 2014
The biggest myth about wireless is that it is not secure. Wireless is only as secure as it is made. Most wireless APs come with several security settings. Many devices default to the WPA (Wireless Protected Access). This security protocol is based on EAP (Extended Authentication Protocol) and uses both a pass key and a group key to maintain a secure environment. WPA outlines the use of several encryption protocols, TKIP (Temporal Key integrity protocol), and in version 2 of WPA, AES (Advanced Encryption Standard). TKIP has become less secure over the years but AES remains secure.
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By Jackson Corson - June 16, 2014
Each transmission burst in 802.11 requires a guard interval that makes it so transmissions do not interfere with one another. Normally this is an 800ns timer that allows for time between bursts. This gives a safe time between transmissions. 802.11n outlined the idea of a short guard interval, decreasing the timer to 400ns. This gives less time between transmissions, which could potentially cause collisions between transmissions from the same device. In tests done in a closed environment, there was a definite increase in packet error rate. Without SGI, there was little to no packet error. With SGI, we saw a 30% increase in packet error rate. This is a significant increase in error, meaning that far more collisions are occurring. However, the throughput of a BSS using SGI was significantly better than a BSS that does not. While the error increased as predicted, the error did not affect the much higher rates that SGI predicted. Is this true in an uncontrolled environment?
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By Jackson Corson - June 4, 2014
Channel bounding has drastically increased the bandwidth of a BSS (Basic Service Set). With 128 Data subcarriers, transmissions can carry far more coded bits per burst. The issue is that this bounded channel increases the number of channels with noise on them. This means more overlap can occur between WLANs operating within the spectra. As a result of this, channel bounding is not advised in the 2.4 GHz because it will make non overlapping channels no longer independent due to the signal spilling into overlapping channels.
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By Jackson Corson - May 22, 2014
Modulation schemes have not changed much in 802.11, since the early days we used OFDM (Orthogonal Frequency Division Multiplexing). 802.11b was really the only notable 802.11 PHY (physical layer) standard that did not use OFDM but then again it did only get 11Mbps using DSSS (Direct-Sequence Spread Spectra). OFDM is the primary modulation suite used for today’s technology. This is because of the super extensible QAM (Quadrature Amplitude Modulation) with BPSK (Binary Phase Shift Keying), and QPSK (Quadrature Phase Shift Keying) handling the simpler modulation.
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By Paul Willis - May 19, 2014
The priorities and specifics of physical limitations differ between standards. For instance Mobile Industry Processor Interface (MIPI) physical layer (PHY) specifications prioritize low power consumption and low electromagnetic interference (EMI) whereas an enterprise storage specification such as Serial Attached SCSI (SAS) focuses on high bandwidth and reliability. The MIPI protocols that are tested at the UNH-IOL are designed for video streaming while SATA is for transmission of Block Storage data. Both send bursts of data with headers and footers to manage erroneous bits. In MIPI the breaks between bursts are relatively short because one line of pixels is usually contained in one burst. After each MIPI burst there is also a break where the transmitter stops sending data, and the receiver stops terminating the signal line, to save on power. The MIPI PHY Specification specifies the timings and voltage levels necessary for entering and exiting this low power mode. SATA on the other hand, does not take breaks between bursts. Once one frame is finished, another is sent. If no data needs to be sent, idle data is shared to maintain the connection.
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By Jackson Corson - May 14, 2014
The IEEE 802.11 specification has proven to be a very reliable way to do networking. Wireless LANs (Local Area Networks) are capable of achieving Gigabits of speed with little to no effort. This makes wireless a competitor with Ethernet and many other networking technologies. But is it as reliable and will it continue to be so?
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By Samantha Martell - April 8, 2014
The University of New Hampshire InterOperability Laboratory (UNH-IOL) has a dual mission to the foster multi-vendor interoperability and also the education and empowerment of the next generation of engineers. On March 19, 2014, the UNH-IOL participated in Girls Technology Day which was hosted at NHTI in Concord, NH. Girls Technology Day is one of many STEM events that the UNH-IOL participates in. This event was developed to expose middle and high school girls to the opportunities and careers available in STEM.
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