w i re 1 css ne two rks, ii n d opt ica I switching. He has organizcd several work- .... tral density (PSD) of signals (Appendix. A) and exactly how binary, M-ary, and.
BOOKREVIEWS (Continued fr-om page 22)
OSPF routers, the reader is introduced to such main concepts as flooding, setting up a hierarchy, and routing calculations. C h a p t e r 4 provides p o r t i n g considerations, while Chapter 5 introduces s o m e basic classes for storing, sorting, and quick searching of various d a t a elements. C h a p t e r 6, one of t h e most interesting, proposes the internal structure of the link-state database, the content of which is used for route calculations. This c h a p t e r also provides m e t h o d s of d a t a b a s e m a n a g e m e n t . Chapter 7 shows in detail in which circumstances a n d how a r o u t e r generates link-state advertisements (LSAs). Chapters 8 and 9 address other important functions: the process of discovery a n d m a i n t e n a n c e of r o u t i n g neighbors (setting u p ncighbor relationships), a n d t h e reliable flooding mechanism which ensurcs a consistent view of the network by all routers and is critical to ensuring rcachability and loop-free routing. Chapter I O clarifies the concept of OSPF areas, area aggrcgatcs, and virtual links, and shows how thcsc can bc implemented i n the soft-
ware. It also discusses t h e e x t e r n a l routing and stub areas. C h a p t e r 11 is devoted to routing calculations based on the raw topology data of the l i n k state database. These include consistency checks of the LSAs, and intra-, inter-, and transit-area routing calculations including equal cost paths (multipath calculations). The implementation of m u l t i c a s t e x t e n s i o n s follows in C h a p t e r 12. C h a p t e r 13 discusses a rich set of configuration p a r a m e t e r s that affect the properties and dynamics of the protocol. The attached CD-ROM is very interesting a n d valuable. I t c o n t a i n s t h e c o m p l e t e C + + s o u r c e c o d e of t h e OSPF routing daemon for Linux, and the OSPF routing simulator ospf-sim, which can be run under Linux or Windows. l'hesc add-ons perfectly corrcspond to the contcnt of the hook and complement it. C h a p t e r 15 dcscribcs the functionality of thc simulator. S u m ni a r i z i n g , t h e book p r o v i d c s extensivc high-quality documentation f o r quality s o u r c c c o d c . For O S P F e x p c r t s i t is a n u l t i m a t e s o u r c e f o r details of complex interactions prcscnt i n the rc a I - t i me d i s t ri bu t cd pro t oco I .
48 Hour Holdover Rubidium Stability Competitively Priced Smallest Available it must be X72.
For distributed networking software developers it is a good case study of how to design such a complex system in a structured way. T h e book also provides numerous interesting techniques t h a t o p t i m i z e t h e efficiency of t h c i m p l e m e n t a t i o n , a n d hints for t h o s e who would like to port the software to other hardware platforms or operating systems.
DIGITALMODULATION TECHNIQUES FUQINXIONG, ARTECHHOUSE,2000, ISBN: 0-89006-970-0, 674 PAGES REVIEWEDBY ERIC BOBINSKY Digital Modulntion Techniques is a s e If - c o n t a i n e d , c o m p r e h e n s ive a 11d detailed synthesis of nearly cvery digital modulation technique in use today. The author, a professor of electrical engineering at Cleveland State Univcrsity'z Fenn College of Enginccring, has S L I C ccedcd admirably at the ambitious t x k of bringing togcthcr information that is largely scattcrcd throughout t h c engineering litcriiturc :tiid prcscnting i t i n ;I ( C o i i r i i i i t c ~ t lO I I p
q c 20)
Our X72 provides vital timing for CDMA cellular and PCS networks. The low temperature coefficient and excellent frequency stability extend holdover performance when GPS signals are not available for 48 hours. And if you can't get to your base station immediately after an equipment failure, X72 provides at least 2 days of precise, stable timing!
A wide range of output frequencies
1&8
Win an Atomic Clock!The
b;. %
. I
most accurate clock you can buy Come by our booth and enter to win1 One dock given away each day'
~
-