Archive for the ‘Telecom and Networking’ Category

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Surveillance system to monitor mobile phones

Monday, November 7th, 2011

Met police using surveillance system to monitor mobile phones article from theguardian magazine article tells that civil liberties group raises concerns over The Metropolitan police purchase of technology to track public handsets over a targeted area.

Britain’s largest police force is operating covert surveillance technology that can masquerade as a mobile phone network. This allow authorities to intercept SMS messages and phone calls by secretly duping mobile phones within range into operating on a false network, where they can be subjected to “intelligent denial of service”. The surveillance system has been procured by the Metropolitan police from Leeds-based company Datong plc. The disclosure has caused concern among lawyers and privacy groups.

This is just one new way to do mobile phone surveillance. Mobile phone surveillance has been possible in many ways earlier. Mobile Surveillance – A Primer highlights some of the potential surveillance risks posed by the use of mobiles. It is the nature of mobile cellular systems that the network operator knows the approximate location of all phones currently on the network, as well as maintaining extensive call and messaging records. And all data and voice you send and receive goes through the operator systems.

tonyk_phone

Posted in Mobile, Security, Telecom and Networking | 1 Comment »

ACTA and SOPA – looks bad

Tuesday, November 1st, 2011

ACTA, the Anti-Counterfeiting Trade Agreement, is a punishing, secretly negotiated copyright treaty that could send ordinary people to jail for copyright infringement. ACTA would establish a new international legal framework that countries can join on a voluntary basis and would create its own governing body outside existing international institution. ACTA has been negotiated in secret during the past few years.

Sounds somewhat worrying to me. ACTA has several features that raise significant potential concerns for consumers’ privacy and civil liberties for innovation and the free flow of information on the Internet legitimate commerce. What is ACTA? document gives details on the agreement. The EU will soon vote on ACTA.

La Quadrature ACTA web page says that ACTA would impose new criminal sanctions forcing Internet actors to monitor and censor online communications. It is seen as a major threat to freedom of expression online and creates legal uncertainty for Internet companies. For some details read La Quadrature’s analysis of ACTA’s digital chapter.

La Quadrature du Net – NO to ACTA video (one side of the view):

The Free Software Foundation (FSF) has published “Speak out against ACTA“, stating that the ACTA threatens free software by creating a culture “in which the freedom that is required to produce free software is seen as dangerous and threatening rather than creative, innovative, and exciting.

ACTA has been negotiated in secret during the past few years. It seem that nobody can objectively tell us what ACTA is going to do. You should oppose it for this exact reason. What exactly it will do is so multi-faceted and so deeply buried in legal speak it requires a book or two to explain.

If you don’t like this you need to do something on that quick. The European Parliament will soon decide whether to give its consent to ACTA, or to reject it once and for all. Based on the information (maybe biased view) I have read I hope the result will be rejection.

Another worrying related thing is Stop Online Piracy Act (SOPA). The bill expands the ability of U.S. law enforcement and copyright holders to fight online trafficking in copyrighted intellectual property and counterfeit goods. The bill would authorize the U.S. Department of Justice to seek court orders against websites in U.S. and outside U.S. jurisdiction accused of infringing on copyrights, or of enabling or facilitating copyright infringement. Proponents of the bill say it protects the intellectual property market. Opponents say it is censorship, that it will “break the internet”, cost jobs, and will threaten whistleblowing and other free speech.

I don’t like this SOPA plan at all, because the language of SOPA is so broad, the rules so unconnected to the reality of Internet technology and the penalties so disconnected from the alleged crimes. In this form according what I have read this bill could effectively kill lots of e-commerce or even normal Internet use in it’s current form. Trying to put a man-in-the-middle into an end-to-end protocol is a dumb idea. This bill affects us all with the threat to seize foreign domains. It is frankly typical of the arrogance of the US to think we should all be subject their authority.

Posted in Telecom and Networking, WWW dev | 143 Comments »

Bitbang Ethernet

Sunday, October 30th, 2011

Implementation UDP into microcontroller Igor Atmel-UDP device:
UDP/IP infrared remote control web page shows implementation UDP/IP on firmware level (similar as emulation of RS232 interface or USB interface).

UDP_IP_computer_infrared_remote_control

What makes it really cool is that the ethernet is bitbanged using nothing but the bare pins of an ATMEGA168. The downside is that this Ethernet implementation is 10 Mbit/s transmit-only: it cannot receive network packets. In think this is a cool hack, that could be enough for some projects.

By the way ATMEGA168 is same chip as used on Arduino Diecimila. Maybe this idea could be adapted to Arduino boards as well if the board is modufied for this (Arduino runs on 16 MHz, this circuits needs 20 MHz clock).

If you want a real full standard Ethernet interface that can transmit and receive, you need to use a real Ethernet controller for it (Ethernet chip or interface built into the microcontroller).

Posted in Arduino, Electronics Design, Telecom and Networking | 1 Comment »

UN wants two-thirds of the world online by 2015

Wednesday, October 26th, 2011

Broadband technologies are fundamentally transforming the way we live. UN believes that communication is not just a human need – it is a right. The greater communication and understanding made possible through access to information and communication technologies. In today’s challenging economic climate, recent research has shown that broadband infrastructure and services contribute to economic growth and promote job creation.

UN wants two-thirds of the world online by 2015 article says: Freedom to communicate is a human right – as is having a broadband connection, the UN said today.

By 2015, internet user penetration should reach 60 per cent worldwide, 50 per cent in developing countries and 15 per cent in least developed countries. They want 40 per cent of households in developing countries to have internet access.

1312903882

Governments should lift taxes on ICT services and free up radio frequency spectrum to fuel an expansion of networking, the UN recommends in its Broadband Challenge issued on Tuesday. Businesses should work out some smarter business models and the prices should come right down.

Connectivity is necessary, but not sufficient. Hand in hand with the roll-out and deployment of broadband networks, it is vital to develop new services, personalized applications and fully multilingual content to ensure that everyone finds their place in the global village online.

If this vision holds there will be lots of work for people that build and maintain the needed access networks. And there there will be lots of work to create that multilingual content.

Posted in Mobile, Telecom and Networking, WWW dev | 3 Comments »

FPGA-based Ethernet switches

Monday, October 17th, 2011

Ethernet switches are the ubiquitous building block of any intelligent network. Ethernet technology is deployed in virtually every organization’s data center. Wide Area Networking (WAN) and Metropolitan Area Networking (MAN) providers need to provide their customers with Ethernet services. Ethernet has also become the de facto networking technology in industrial automation even in mission-critical local networks. Modern Ethernet switches have added significant new functionality to Ethernet while decreasing port prices.
switch_hp_stack_xx_nic_
FPGA-based Ethernet switches for real-time applications article tells that Lattice Semiconductor and Flexibilis have released a Gigabit Ethernet Switch IP core that is scalable, non-blocking, and extensible. The article also discusses on different Ethernet applications and requirements they need. Article tells about deterministic and synchronized real-time operation, IEEE-1588-2008 (v2) Precision Timing Protocol, redundancy, High-Availability Seamless Redundancy (IEC 62439-3) and how FPGA implementation works for those.

lat-03

Posted in Electronics Design, Telecom and Networking | 7 Comments »

10GBase-T Technology

Thursday, October 6th, 2011

The growing importance of cloud computing along with the increasing utilization of unified data/storage connectivity and the advent of server virtualization have elevated the popularity of 10Gbps Ethernet.There are several connectivity options are available for 10Gbps Ethernet, both over optical fiber and copper cables.

10GBase-T Technology Revisited article tells that the lack of economical cabling options for 10G Ethernet beyond a single or adjacent rack has led to the popularity of Top-of-Rack (ToR) architectures, in which a stack of rack mounted servers are connected with short cables to a fixed configuration switch in close proximity — typically on top of the server rack.

10GBase-T has promise to change that. 10GBase-T is the fourth generation of IEEE standardized Base-T technologies which all use RJ45 connectors and unshielded twisted pair cabling to provide 10Mbps, 100Mbps, 1Gbps, and 10Gbps data transmission, while being backward-compatible with prior generations.

10GBase-T is arguably the most flexible, economical, backward-compatible, and user-friendly connectivity option available. 10GBase-T allows you to use the existing structured cabling infrastructure and allows cable to reach to the full 100-meter length permitted by structured cabling rules. When compared to other 10Gbps connectivity solutions, one of the most important advantages of 10GBase-T is the ability to communicate and inter-operate with legacy, often-slower Base-T systems.

IEEE 802.3an, 10-Gigabit Ethernet over twisted pair standard, also known as 10GBase-T, was ratified at 2006. Unfortunately this has not led to an immediate proliferation of compliant switches and servers in data centers. However, steady advances in semiconductor lithography, and sophisticated algorithms intended to increase electromagnetic interference (EMI) immunity and lower operating power, will make it more practical. For years 10GBase-T has been considered to be very power hungry and expensive. The reason for this has been the complexity of the signal processing that is needed. The 10GBase-T transceiver uses full duplex transmission with echo cancellation on each of the four twisted pairs available in standard Ethernet cables; thereby transmitting an effective 2.5Gbps on each pair.

10GBase-T Technology Revisited article will explore the basic operation of a 10GBase-T transceiver and the inherent advantages of 10GBase-T technology as compared to alternatives, such as optical fiber and coaxial copper.

One of the arguments against 10GBase-T has been power dissipation, but this perspective is rooted mostly in early implementations of the technology. Recent advances in semiconductor lithography have allowed 10GBase-T transceivers to enjoy a dramatic reduction in the power they dissipate during normal operation. From a per-port power of over 6W just a few years to typical Active power dissipation of 1.5W. When utilizing the EEE power saving algorithm with typical computer data patterns for 30-meter reach, newest ICs will dissipate only 750mW.

Gigabit_Layer_2_Switch

Posted in Computers, Telecom and Networking | 5 Comments »

Wi-Fi for Video

Tuesday, October 4th, 2011

Meeting the requirements for video-grade Wi-Fi Access Points article gives some interesting facts on transporting video over wireless LAN. Users are coming to expect a wireless video experience equivalent to video consumption over wires.

Traditionally a Wi-Fi device was measured according to its receiver performance, using metrics such as receive sensitivity. With video delivery, transmitter performance is ultimately measured according to user experience. Raw throughput is no longer an adequate metric for measuring wireless network performance, as was the case with internet data traffic.

boton_wifi

If we use around 10-20 Mbps per HD stream, multiple HD stream delivery requires no more than 40-80 Mbps of actual throughput. The main challenge is to deliver this relatively modest throughput consistently and robustly across an entire home to multiple nodes. Quality-of-service (QoS) related metrics, such as packet loss, delay and jitter, to which HD video is highly sensitive, must be optimized as well, sometimes at the expanse of raw throughput.

This must be accomplished over a constantly changing and hostile wireless fading, interference prone channel. The challenge becomes converting an unpredictable medium into a controlled and managed one. We can’t control everything, but we need to make the system to work well enough to be enjoyable.

rg1024_old_television_2.0

Posted in Audio and Video, Telecom and Networking | No Comments »

Cat 5 Cable Modeling

Thursday, September 22nd, 2011

Category 5 (CAT5) cable is a multi-pair (usually 4 pair) cable that consists of twisted pair conductors, used mainly for data transmission. Basic CAT5 cable was designed for characteristics of up to 100 MHz. Newer CAT6 cable is designed form 250 MHz. Nowadays there are applications where those cables is used to carry higher frequencies.

cat5utp

Cat 5 Cable Modeling for DVI/HDMI links tells how to analyze the cable performance. The behaviour of each twisted pair is determined by the complex three-dimensional
electromagnetic field in the region within and surrounding the cable. For communications link performance verification we require a simplified representation of the cable that is computationally viable and can be included within the circuit verification environment. The model also needs to correctly represent important cable parameters such as delay, near and far end crosstalk and cable losses.

utpmodel

Cat 5 Cable Modeling for DVI/HDMI links article gives a simple C++ module was written and added to the CppSim behavioural modelling environment. The article also gives a Hspice ‘W’ model.

The combination of field solver and multi-conductor W model in Hspice can be used to simulate all the key signal degradation characteristics such as frequency dependent loss, delay, near and far end coupling and the effect of discontinuities for different UTP cable geometries.

jasonfilley_Network_Cable

Posted in Audio and Video, Electronics Design, Telecom and Networking | 1 Comment »

Weird Voltages in a PoE Camera System

Friday, August 12th, 2011

It seems that there is a trend to convert video systems over from an old, all-analog system to a modern, IP-based system with cameras powered over the Ethernet line using PoE (Power over Ethernet).

Weird AC Voltages in a PoE Camera System post at Control Geek Blog talks about an interesting PoE (Power over Ethernet) issue I found with some IP cameras and some switches.

Weird AC Voltages in a PoE Camera System–Followup gives some more details and analysis of the problem. And if you are really interested in the details check also Interesting PoE problem discussion at The Show Control Mailing List.

Posted in Audio and Video, Electrical power, Groundloop, Telecom and Networking | No Comments »

World’s first GSM call, 1 July 1991

Friday, July 1st, 2011

World’s first GSM call, 1 July 1991

Posted in Mobile, Telecom and Networking | 1 Comment »

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