
Thursday, September 25, 2008
Sunday, September 14, 2008
BIOMETRIC RECOGNISATION
Monday, September 1, 2008
MICROPHOTONICS
Microphotonics is a branch of technology that deals with directing light on a microscopic scale. It is used in optical networking.
Microphotonics employs at least two different materials with a large differential index of refraction to squeeze the light down to a small size. Generally speaking virtually all of microphotonics relies on Fresnel reflection to guide the light. If the photons reside mainly in the higher index material, the confinement is due to total internal reflection. If the confinement is due many distributed Fresnel reflections, the device is termed a photonic crystal. There are many different types of geometries used in microphotonics including optical waveguides, optical microcavities, and Arrayed Waveguide Gratings.
PROBLEM WITH IPHONE -chip related
Om has complained about his frustration with the 3G iPhone, which has poor reception and forces him to spend more time on the 2.5G EDGE network than he thought, but the issue may be with Infineon’s 3G chip, according to Richard Windsor, an analyst with Nomura Securities. In a research note today, he said: “We believe that these issues are typical of an immature chipset and radio protocol stack where we are almost certain Infineon is the 3G supplier.” That comment might cheer AT&T, but it’s bad news for Infineon, and perhaps a warning to the chip industry about quality control.
Windsor writes that the problem isn’t likely to be solved with firmware updates, which means Apple could have to replace the chips so users get the performance they were promised. If the chip is the problem, this would be the second large chip failure this summer, with Nvidia’s faulty graphics chips placed in thousands of laptops grabbing most of the headlines so far.
The Nvidia issue appears to be caused by poor packaging, and the company has taken a $150-$200 million charge related to fixing the problem, but neither OEMs nor end customers are happy about the situation — especially Nvidia’s reluctance to disclose the full scope of the failure. I’ve emailed Infineon to see what they have to say about the iPhone chip and whether they make it themselves or outsource production as Nvidia has done with its graphics chips, but given Apple’s tendencies we might have to wait a while until we know the truth.
Thursday, July 31, 2008
bras
A broadband remote access server (BRAS or BBRAS) routes traffic to and from the digital subscriber line access multiplexers (DSLAM) on an Internet service provider's (ISP) network.
The BRAS sits at the core of an ISP's network, and aggregates user sessions from the access network. It is at the BRAS that an ISP can inject policy management and IP Quality of Service (QoS).
The specific tasks include:
Aggregates the output from DSLAMs
Provides user PPP sessions over IP or ATM sessions
Enforces quality of service (QoS) policies
Routes traffic into an Internet service provider’s backbone network
A DSLAM collects data traffic from multiple subscribers into a centralized point so that it can be uploaded to the router over a Frame Relay, ATM, or Ethernet connection.
The router provides the logical termination for PPP sessions. These may be PPP over Ethernet (PPPoE) or PPP over ATM (PPPoA) encapsulated sessions. By acting as the PPP termination point, the BRAS is responsible for assigning session parameters such as IP addresses to the clients. The BRAS is also the first IP hop from the client to the Internet.
The BRAS is also the interface to authentication, authorization and accounting systems (see RADIUS)
Saturday, July 26, 2008
ahemdabad and bangaluru serial blast rocks india
AHMEDABAD: Terror struck Gujarat when 17 serial blasts ripped across the city on Saturday evening leaving 15 killed and 30 injured sending a wave of panic. The synchronised explosions in the space of 90 minutes in the eastern and western areas after the first blast hit Maninagar at 6.45 pm occurred in 13 places. There were two blasts each in Maninagar--the constituency of Chief Minister Narendra Modi--and in Sarkej targeting a state transport CNG bus and Sangam theatre. Significantly two hospitals were also the target of attack. An NSG team has been rushed to Ahmedabad. The low-intensity explosions occurred at eight areas of Maninagar, Isanpur, Narol circle, Bapunagar, Hatkeshwar and Sarangpur bridge, Sarkej and Odhav and created a wave of panic. There were two blasts in Maninagar and the first blast occurred in this area at 6.45 PM. The second blast here occurred near LG hospital. Maninagar is the constituency of Chief Minister Narendra Modi. The Ahmedabad blasts came a day after the multiple explosions in Bangalore in which two persons were killed. The mobile network in the area has completely collapsed. Police said at least two had died and 25 injured, some of them seriously, in the blasts. The injured have been rushed to civil hospital and LG hospital. Union Minister of State for Home Sriprakash Jaiswal said in New Delhi there were eight blasts. Unconfirmed reports said there were 13 blasts. The explosion in the sensitive Sarkej area occurred in a CNG bus. Some of the bombs were believed to have been placed in cycles eerily similar to the Jaipur blasts on May 13 in which 65 persons died. A couple of bombs were reported to have been placed in tiffin boxes in a modus operandi similar to the explosions outside a Lucknow court last year. |