标签: telecommunications

I've recently started to consider whether or not it would be right and proper for me to perform an experiment on a member of my family.     The modern world in the form of today's telecommunications systems couldn’t have come at a better time for my wife (Gina the Gorgeous). As we lay in bed at night, I fall asleep to the gentle "ping" sounds of incoming emails and text messages arriving on her various smartphone and tablet devices.   The funny thing is that Gina is rarely in the same room as her mobile devices -- she's set up a sort of "command and control" center in a corner of the kitchen where these little rascals are typically to be found basking on the counter gorging themselves on electricity (or charging, if you prefer).   As an aside, this reminds me of my mother, who has developed the uncanny ability to be at the farthest possible distance from her purse in whatever building she is currently residing. If she's in a downstairs room on the northeast corner of my brother's house, for example, then you can bet your life that her purse will have found its way to the far side of an upstairs bedroom on the southwest corner of the building, and vice versa. It's as though the purse has a life of its own.   Of course, my mother constantly decides that she needs access to something in her purse. And, of course, someone else (like yours truly) is invariably dispatched to track the little rascal down. The amazing thing is that, just a few minutes later, we will find ourselves in another part of the house sans la bourse . It's like magic. If she decided to perform this as an act on the variety hall stage I could retire. But we digress...   A typical evening will find Gina and myself relaxing in our family room. It may be that I am in the middle of regaling Gina with a tale of engineering derring-do when a "ping" comes from the kitchen. It's like watching a Pavlovian performance. Her hand starts to twitch and she begins squirming in her chair. Eventually she can restrain herself no longer; she will leap to her feet and -- with a "Hold that thought!" -- she will race away to see what earth-shattering news has arrived from the outside world.   Sad to relate, the thought cannot be held. By the time Gina returns, I've completely forgotten what we were talking about. It's very frustrating because I'm sure it would have been a very funny story. Undeterred, I may commence another conversation, only to be interrupted by a new "ping."   When this happened yesterday evening, I started thinking that it might be fun to create a wireless device whose sole function was to go "ping." I could hide this gizmo in the vicinity of Gina's smartphones and tablet computers and then trigger the little scamp using a companion device hidden in my pocket. Just a few seconds after Gina started to tell me one of her stories, I could instigate a "ping" in the kitchen.   The more I come to think about it, the more I'm attracted by this idea. It could come in very handy on those occasions when Gina finds herself forced to remind me of the myriad things she needs me to do around the house. As soon as I detected such an occurrence on the horizon, a "ping" could emanate from the kitchen, and I could raise a quizzical eyebrow that practically shouts "I wonder who that could be."   The great thing is that Gina receives so many messages on so many devices that I'm sure she'd get distracted by other items that were already there. I wonder how long it would take her to realize what was happening. I also wonder how many of these devices I could sell.

I was reading a technical-review article the other day and saw the word "erlangs." All I could think was, "wow, I haven't seen that word in a while!" Back in the day, if you were involved at all with telecommunications, system analysis, or telephony (another fading term, BTW), you knew about erlangs. "What's an erlang, anyway?" you're asking. To quote from this site , "an Erlang is a unit of telecommunications traffic measurement. Strictly speaking, an Erlang represents the continuous use of one voice path.ÿIn practice, it is used to describe the total traffic volume of one hour." The erlang parameter is based on the idea of a circuit-switched network, with a physical line dedicated to the voice call in progress. By knowing how many erlangs of traffic you had, you could determine how many physical circuit lines you needed in a phone system, whether to serve a business office, or a phone company central office, or for trunk lines between central offices. There are tables and formulas which showed resources needed to provide different thresholds of system availability, for any given number of erlangs of voice traffic. Things have certainly changed. A dedicated circuit line for a voice call is largely an anachronism, as we now digitize voice, break the resultant data streams into packets, and route them via a packet-switching network. We think of system capacity in terms of bandwidth, data rates, bit error rate, throughput, and other parameters — not erlangs. So the erlang, which served the industry well and was the basis for so much system design and provisioning, has dimmed severely in the lexicon of the telecom engineer. That's how things go in our high-tech world: for a while, you're vital; later on, you're perhaps just a footnote. Are there any technical terms that you used to see, but no longer do? Are there terms you see which wished you knew what they were about, and why they were used?  

The sun can be the cause of more than just a nasty sunburn in the world of technology.  Harmful solar radiation can, in certain instances, cause satellites to experience glitches, lose communications with earth, and even damage incredibly expensive components.  One such instance, a major coronal mass ejection (CME) triggered by sun spot "930" in late 2006, forced numerous satellites to power down or go into "safe mode" in order to avoid damage.  In the past these CMEs have knocked out satellites and tripped terrestrial power grids.  These storms can arrive in moments with little warning, and in the future it is quite possible that an even larger storm could cause irreversible damage to communications systems the world over.   In addition, for Low Earth Orbit satellites at or around 6,000 km orbit face increasing difficulties with the South Atlantic Anomoly (SAA), an ever growing spot between Brazil and Southern Africa where the earth's Van Allen belt of electro-magnetism is weakening.  Since it's discovery in the 1950's its borders have grown steadily in the North, Northwest, Northeast, and East.   When satellites within this orbital range pass through the SAA it is necessary for them to shut down as they recieve abnormally high proton bombardment exceeding 10 million electron volts.  As the region continues to expand, with several scientists believing this may be the beginning of a full polarity shift, it will become increasingly important for telecommunications, aerospace, and satellite designers to seek long term solutions to avoid very costly and irreversible damages.   One theory, stumbled onto by an international team of scientists in 2008 is to bathe the skies in radio waves.   The scientists indicated that magnetospheric electrons can be discharged into the atmosphere by using ground-based radio transmitters.   In the future, during periods of intense solar activity there could be a system in place to bathe the sky in radio waves, allowing the safe passage of satellites.   While this is still largely untested, it represents an exciting possibility for the future of this industry.  In the near future, the sun, man's greatest ally, may pose a very real problem for our telecommunications and aerospace industries.  If we are aware and prepared, hopefully this issue can be overcome in order to save millions of dollars in potential damages.