标签: communication

Funnily enough, just several days ago as I write this blog, I was chatting with my wife (Gina the Gorgeous) when she informed me that -- as a kid -- she had never played at making a telephone using two tin cans connected by a piece of string.   I must admit to being a tad surprised. I thought every kid was obliged to do this as a rite of passage or something. Even now that I'm old and gray, I'm not above playing with this sort of thing. Everyone should have a little whimsy in their lives. (I know, I know … it's not the size of your little whimsy, it's what you do with it that counts, but we digress …)   So, you can only imagine my surprise on discovering the ultimate in iRonic gifts -- the iCups communication system, which is billed as "The apex of high fashion and high technology, and the perfect gift for the trendiest of friends and family!" As you can see in the photograph below, being presented with his very own iCups communications system certainly brightened Steve Wozniak's day.     I think it's fair to say that, in this increasingly complex technological world in which we live, the retro iCups system takes us back to a simpler, purer time.     What, you want an iCups system of your very own? Well, in that case I'm about to bring a smile to your face and brighten your day, because Magdim Mukhametshin, co-founder of ADA Sport, has an iRonic iCups Kickstarter project up and running.   Why do these folks need a Kickstarter? Well, as Magdim says, quite apart from anything else, they need to be prepared for the onslaught of lawsuits from the phone companies whose business they'll be stealing! Knowing how litigious companies are these days, it's hard to argue with this.   I must admit that I'm tempted by the Special Christmas Edition, which is based on the regular 64-inch model power-boosted by special edition red Christmas string. I was tempted by the LD model, with a 128-inch string for long distance communications, which is claimed to be "Ideal for kids with tree houses, members of the neighborhood watch, and local law enforcement!" Sad to relate, this option has already been snapped up.     And what of the technology powering this revolutionary system? Well, as soon as I take delivery of my iCups system, I may feel moved to undertake a technology teardown. Watch this space …

The two books that I constantly refer to are by Andrew S. Tanenbaum and William Stallings. These two are both experts on computer networking and data communications. " Data and Computer Communications ," a textbook first published in 1997 and is now in its ninth updated edition, is by Stallings. Tanenbaum, this time with David J. Wetherall, is the author of " Computer Networks ," first published in 1981 and now in its fifth edition. I have had both textbooks since they were originally published and make it a point every few years to go out and obtain the latest revised edition is because they both do an excellent job of updating them, either through new sections and chapters or, more often, by going through the text line by line and changing previous information in the context of what has been learned in later years. But in the newest 2011 editions of their books both authors have outdone themselves, adding not only a lot of new information, but many enhancements that make understanding the technical information easier. I would be hard pressed to choose which author is my favorite. I read both for their different perspectives on some of the same issues. Also, one may give more emphasis and detail on some topics than the other. But between the two, I know I have all my bases covered. So, if you have the time, and money, I would recommend getting both books. The new stuff in Tanenbaum's Fifth Anyone who battles to stay on top of what is going on in networking and data communications will appreciate the work that Tanenbaum and Wetherall have put into this newest version of their book. Chapter 1 has the same introductory function as in the fourth edition, but the contents have been revised and brought up to date with new information on mobile and wireless phones, 802.11, RFID and sensor networks, but material on the original Ethernet—with its vampire taps—has been removed, along with the material on ATM. Chapter 2, on the physical layer, now includes digital modulation (including OFDM as widely used in wireless networks) and 3G networks (based on CDMA) as well as some discussion of Fiber to the Home and power-line networking. Chapter 3, on point-to-point links, has been improved in two ways. First, the material on codes for error detection and correction has been updated, and second, a description is included of the modern codes that are important in practice (e.g., convolutional and LDPC codes). Particularly useful are the examples of protocols regarding Packet over SONET and ADSL. The basic principles of the MAC sublayer covered in Chapter 4 are essentially the same, but the example networks they have included have been redone extensively to include gigabit Ethernet, 802.11, 802.16, Bluetooth, and RFID. Also updated is the coverage of LAN switching, including VLANs. While Chapter 5, on the network layer, covers the same ground as the earlier editions, it has been updated and expanded with reference to quality of service (relevant for real-time media) and internetworking. The sections on BGP, OSPF and CIDR have been expanded, as has the treatment of multicast routing. Anycast routing is now included. In Chapter 6, on the transport layer, there is new material describing delay-tolerant networking and congestion control, and revised material updates. The coverage of TCP congestion control has been expanded. Removed, though, is any discussion of connection-oriented network layers, something rarely seen anymore. In Chapter 7, on applications, the material on DNS and email is similar to the earlier edition, but the sections on the Web and streaming media have been brought up to date. A new section covers content distribution, including CDNs and peer-to-peer networks. Chapter 8, on security, still covers both symmetric and public-key cryptography for confidentiality and authenticity. Material on the techniques used in practice, including firewalls and VPNs, has been updated, with new material on 802.11 security and Kerberos V5 added. Most interesting to me – glutton for information that I am – is the bibliography in Chapter 9, which has been updated and expanded to 300 citations of the current literature, more than half to papers and books written since 2000. Improvements to Stallings book In addition to an impressive number of examples to illustrate some of the technical content, Stallings has made extensive changes in this new edition that will be enormously useful. For example, this new edition covers the 2009 ANSI/TIA 568-C standards and the recent ISO/IEC 11801 twisted-pair transmissions, which are important for gigabit-range Ethernet and other high-speed twisted-pair applications. There is also new coverage of virtual LANs, specifically VLAN technology, as well is the IEEE 802A Q standard. There is updated coverage of high-speed Ethernet including not only the new 100-Gbps standard but the multilane distribution (MLD) transmission technique as well, and expanded coverage of 6413/6613 encoding. Stallings has also updated his coverage of Wi-Fi/IEEE 802.11 wireless LANs. New coverage includes 802.11 as well as Mobile IP, which standardizes techniques for IP addressing and routing for mobile end systems. New to this edition is a full chapter devoted to Multiprotocol Label Switching, which is becoming increasingly important on the Internet and other IP-based networks as well as in telecommunications networks. Finally, the coverage of security has been completely rewritten and expanded to two chapters. As Tanenbaum and Wetherall have done, throughout his book Stallings has taken care that virtually every topic has been updated to reflect the developments in standards and technology that have occurred since the publication of the earlier edition. Additional online content Targeted primarily at students using these books in college courses, the publisher—Pearson Education/Prentice Hall—has augmented the printed and ebook versions of the textbooks with a tremendous amount of online content . There is so much that is useful I would be tempted to go back to school to gain access to more of it. For the Tanenbaum book there is a resources page on co-author Weatherall's site at the University of Washington with additional related web resources, links to tutorials, and organizations as well as demos of such things as steganography and an online network protocol simulator. Even more impressive is the online content available for Stallings book at http://williamstallings.com/DataCommunications/ . Two additional chapters to the book are available in PDF form: one on electronic mail, HTTP, and DNS, and the other on Internet multimedia support. There are 20 other supplementary appendices, in addition to the two in the book. The collected technical wisdom in both these books does not come cheap. Stalling's 800 page text book is just under $60 for the ebook version. Tanenbaum/Weatherall's 875 page text it is $128 for the print version and just over $50 for the ebook version. But both are worth the price.

I had a rather interesting night a few weeks ago, because I was invited to give a presentation on the use of social media to a group of inventors in Birmingham, Alabama. I think most of us have certain ideas about inventors. Some people picture them as eccentric scientists. For myself, a vision of Beaker from the Muppet Show usually pops into my head around this point. Speaking of which, do you recall that incredibly funny YouTube video of Beaker playing and singing ODE TO JOY ? Actually, while I think about it, do you know any good quotes about inventors? I think that my current favorite is the one from the English film director Alfred Hitchcock who famously said: "These are bagpipes. I understand the inventor of the bagpipes was inspired when he saw a man carrying an indignant, asthmatic pig under his arm. Unfortunately, the man-made sound never equaled the purity of the sound achieved by the pig." I think that's very unfair. I personally like the sound of the bagpipes. I've even thought about trying to learn the Irish (or Uilleann ) Bagpipes, which are a completely different kettle of fish to the better-known Scottish variety. Something else just popped into my head. Someone once told me that "A gentleman is someone who knows how to play the bagpipes ... but doesn't!" (I think the original quote related to the accordion, but it works just as well for the bagpipes.) I don't know how you do it. You've made me wander off into the weeds again. What were we talking about? Oh yes, my speaking to the inventors. So here's how it all came about... One of my friends – Brian LaGrave of BDH Consulting – is a bona fide inventor who attends the monthly meetings of an inventor's club in Birmingham, Alabama (who knew inventors had clubs?). Anyway, I think they were short of a good speaker for this month's meeting, so they ended up asking me instead (grin). I live in Huntsville, Alabama, which is about 90 miles north of Birmingham. Over the years I have developed a tremendous ability to get lost at the drop of a hat. So I drove a little way down Highway #65 and met Brian and his 13-year old son Sam at a gas station and we car-pooled the rest of the way down. Before we proceed, I'd just like to mention that Sam is a really great young lad – in addition to giving his dad directions to get us to the meeting in the depths of the Birmingham backstreets (and then getting us back out again), he took charge of the audio-visual stuff and controlled the slides on my computer for me, thereby leaving me free to wander around talking and waving my arms around in the air as is my wont. I really enjoyed myself. I would like to tell you about all of the weird and wonderful inventions that these inventive inventors are inventing, but the whole meeting was under a non-disclosure agreement (NDA), which makes a lot of sense because otherwise no one would talk about their inventions. Suffice it to say that I ended up giving a talk that bounced around from topic to topic with the agility of a mountain goat. In addition to social media (the official definition of which is "The use of web-based and mobile technologies to turn communication into interactive dialog." ), we covered a lot of other topics. One point I made was that it's important to get your ducks in a row. When it comes to announcing and promoting an invention, for example, social media only works in the context of a bigger picture. There's no point in creating a "viral happening" that brings hundreds of thousands of people to your website ... only to find one of those annoying "Under Construction" signs. I would tell you more, but I'm hoping that more groups and companies will be interested in my giving the same talk to them, so I think we'll leave the rest shrouded in mystery (he said, mysteriously)...

I had a rather interesting night a few weeks ago, because I was invited to give a presentation on the use of social media to a group of inventors in Birmingham, Alabama. I think most of us have certain ideas about inventors. Some people picture them as eccentric scientists. For myself, a vision of Beaker from the Muppet Show usually pops into my head around this point. Speaking of which, do you recall that incredibly funny YouTube video of Beaker playing and singing ODE TO JOY ? Actually, while I think about it, do you know any good quotes about inventors? I think that my current favorite is the one from the English film director Alfred Hitchcock who famously said: "These are bagpipes. I understand the inventor of the bagpipes was inspired when he saw a man carrying an indignant, asthmatic pig under his arm. Unfortunately, the man-made sound never equaled the purity of the sound achieved by the pig." I think that's very unfair. I personally like the sound of the bagpipes. I've even thought about trying to learn the Irish (or Uilleann ) Bagpipes, which are a completely different kettle of fish to the better-known Scottish variety. Something else just popped into my head. Someone once told me that "A gentleman is someone who knows how to play the bagpipes ... but doesn't!" (I think the original quote related to the accordion, but it works just as well for the bagpipes.) I don't know how you do it. You've made me wander off into the weeds again. What were we talking about? Oh yes, my speaking to the inventors. So here's how it all came about... One of my friends – Brian LaGrave of BDH Consulting – is a bona fide inventor who attends the monthly meetings of an inventor's club in Birmingham, Alabama (who knew inventors had clubs?). Anyway, I think they were short of a good speaker for this month's meeting, so they ended up asking me instead (grin). I live in Huntsville, Alabama, which is about 90 miles north of Birmingham. Over the years I have developed a tremendous ability to get lost at the drop of a hat. So I drove a little way down Highway #65 and met Brian and his 13-year old son Sam at a gas station and we car-pooled the rest of the way down. Before we proceed, I'd just like to mention that Sam is a really great young lad – in addition to giving his dad directions to get us to the meeting in the depths of the Birmingham backstreets (and then getting us back out again), he took charge of the audio-visual stuff and controlled the slides on my computer for me, thereby leaving me free to wander around talking and waving my arms around in the air as is my wont. I really enjoyed myself. I would like to tell you about all of the weird and wonderful inventions that these inventive inventors are inventing, but the whole meeting was under a non-disclosure agreement (NDA), which makes a lot of sense because otherwise no one would talk about their inventions. Suffice it to say that I ended up giving a talk that bounced around from topic to topic with the agility of a mountain goat. In addition to social media (the official definition of which is "The use of web-based and mobile technologies to turn communication into interactive dialog." ), we covered a lot of other topics. One point I made was that it's important to get your ducks in a row. When it comes to announcing and promoting an invention, for example, social media only works in the context of a bigger picture. There's no point in creating a "viral happening" that brings hundreds of thousands of people to your website ... only to find one of those annoying "Under Construction" signs. I would tell you more, but I'm hoping that more groups and companies will be interested in my giving the same talk to them, so I think we'll leave the rest shrouded in mystery (he said, mysteriously)...