WiMax Operator's Manual

More documents

Recommendations

Info

CHAPTER 4 ■ SETTING UP PHYSICAL INFRASTRUCTURE 67 to modify the Transmission Control Protocol/Internet Protocol (TCP/IP) data stream so as to adapt it to the airlink. The design of such boxes is far from uniform, and in the first generation of lower microwave equipment, a modified Data over Cable Service Interface Specification (DOCSIS) cable data headend device was often employed. Today that approach is thoroughly discredited, however, and indeed with the finalization of 802.16 and the production of equipment embodying it, the network operator need not even consider such a makeshift. Generally, the base station transceiver will be combined with the router/switch. Second, the operator will also need an edge router whose output will go directly to the radio transceiver, if the two are not combined in a single box. The size and power consumption of this device will depend on the number of subscribers served. Most edge routers made today are highly modular, consisting of a largish box with multiple slots taking a number of separate blades, each of which handles a group of input/output (I/O) ports. The router is designed for a certain maximum number of ports, and in most cases the operator chooses to buy additional blades as needed until reaching the full capacity of the design. A fully loaded edge router will, as a rule, take up several rack spaces and will have a power consumption in the kilowatts. Carrier-grade edge routers cost thousands of dollars, but a small metropolitan network may be able to get away with an enterprise-class router, which costs less than $1,000. In some cases, as I have mentioned, the base transceiver will incorporate an edge router. Figure 4-1 shows a Juniper edge router. Figure 4-1. A Juniper edge router, courtesy of Juniper Networks Some products that are primarily edge routers perform other functions as well, such as creating services, inputting and outputting protocols other than IP, and providing switching functions within those other transport protocols. Such “Swiss Army knife” network elements are popularly known as godboxes and are intended to provide the network operator with lots of choices and a high degree of flexibility. The utility of such devices is a matter of some contention in the telecommunications world today. Little uniformity exists in the design approaches embodied in godboxes, and any
68 CHAPTER 4 ■ SETTING UP PHYSICAL INFRASTRUCTURE network operator contemplating using such a device must carefully study its capabilities. Depending on the mix of services the operator intends to offer, some such devices may be useful. But typically the versatility comes at a price. The boxes incorporate custom designs and often utilize proprietary elements, architectures, and engineering approaches and, in many cases, represent staggering development costs that cannot be amortized even among a large universe of users. Furthermore, none of the godboxes on the market today have been designed with the specific needs and requirements of the wireless operator in mind; instead most are designed to interface with optical networks. Another essential element in the central office equipment rack is a server devoted to the subscriber database. The same element may, depending on the size of the network and the desire of the operator to assign the various networking functions to discrete physical platforms, also contain the billing and provisioning software and may host the authentication software as well; however, more commonly, in the interest of ensuring the highest degree of security, authentication will be performed on a separate server. Radius authentication software has become the de facto industry standard for telecommunications and large enterprises. The central office may also, again depending on the mix of services, contain such as elements as the following: A softswitch An IP telephony gateway (occasionally the two elements will be combined on one physical platform) A content server for supporting “walled-garden” applications that are not resident upon the public Internet but are available only to those who subscribe to the wireless broadband network A video server for caching multimedia material to be streamed to subscribers or else accessed on demand, or, alternately, for ad insertion A server for content management software A hardware security device for bulk encryption/decryption A satellite transceiver for accessing content An optical transceiver for interfacing with a metro ring or mesh A DSL access multiplexer (DSLAM) for interfacing with DSL links Certainly other network elements are possible as well, and conceivably the central office for a large metropolitan wireless operation could have two or more floor-to-ceiling racks filled with equipment. Any central office, large or small, should occupy a secure location where access to the facilities is strictly controlled and the facilities are monitored at all times. In today’s political climate considerations of physical security are not secondary, and the days when major Internet access points were left untended in unlocked rooms in parking structures are long gone. The central office should have an uninterruptible power supply (UPS) or supplies capable of powering the central office equipment complement for at least 48 hours. Such backup power may utilize banks of batteries, fuel cells, internal combustion generators, or combinations thereof. The important point is that the backup power supplies deliver dependable AC
Page 2 and 3:
WiMax Operator’s Manual Building
Page 4:
This book is dedicated to my wife.
Page 8 and 9:
Contents About the Author . . . . .
Page 10 and 11:
■CONTENTS ix Performing Site Surv
Page 12:
■CONTENTS xi Cyberwarfare . . . .
Page 16:
About the Technical Reviewer ■ROB
Page 20 and 21:
Introduction Broadband wireless has
Page 22 and 23:
CHAPTER 1 ■ ■ ■ Wireless Broa
Page 24 and 25:
CHAPTER 1 ■ WIRELESS BROADBAND AN
Page 26 and 27:
Page 28 and 29:
Page 30 and 31:
Page 32:
Page 35 and 36:
14 CHAPTER 2 ■ ARCHITECTING THE N
Page 37 and 38: 16 CHAPTER 2 ■ ARCHITECTING THE N
Page 55 and 56: 34 CHAPTER 3 ■ STRATEGIC PLANNING
Page 85 and 86: 64 CHAPTER 4 ■ SETTING UP PHYSICA
Page 87: 66 CHAPTER 4 ■ SETTING UP PHYSICA
Page 121 and 122: 100 CHAPTER 4 ■ SETTING UP PHYSIC
Page 123 and 124: 102 CHAPTER 5 ■ STRATEGIES FOR SU
Page 139 and 140:
118 CHAPTER 5 ■ STRATEGIES FOR SU
Page 141 and 142:
Page 143 and 144:
Page 145 and 146:
Page 147 and 148:
Page 149 and 150:
Page 152 and 153:
CHAPTER 6 ■ ■ ■ Beyond Access
Page 154 and 155:
CHAPTER 6 ■ BEYOND ACCESS 133 Rou
Page 156 and 157:
CHAPTER 6 ■ BEYOND ACCESS 135 (Qo
Page 158 and 159:
CHAPTER 6 ■ BEYOND ACCESS 137 The
Page 160 and 161:
CHAPTER 6 ■ BEYOND ACCESS 139 ins
Page 162 and 163:
Figure 6-4. Wireless public network
Page 164 and 165:
CHAPTER 6 ■ BEYOND ACCESS 143 sto
Page 166 and 167:
Specialized Content Distribution Pl
Page 168 and 169:
Beyond the Central Office CHAPTER 6
Page 170 and 171:
CHAPTER 6 ■ BEYOND ACCESS 149 out
Page 172 and 173:
CHAPTER 6 ■ BEYOND ACCESS 151 som
Page 174 and 175:
CHAPTER 7 ■ ■ ■ Service Deplo
Page 176 and 177:
CHAPTER 7 ■ SERVICE DEPLOYMENTS O
Page 178 and 179:
Page 180 and 181:
Page 182 and 183:
Page 184 and 185:
Page 186 and 187:
Page 188 and 189:
Page 190 and 191:
Page 192 and 193:
Page 194 and 195:
Page 196:
Page 199 and 200:
178 CHAPTER 8 ■ NETWORK MANAGEMEN
Page 201 and 202:
Page 203 and 204:
Page 205 and 206:
Page 208 and 209:
CHAPTER 9 ■ ■ ■ Network Secur
Page 210 and 211:
CHAPTER 9 ■ NETWORK SECURITY 189
Page 212 and 213:
Page 214 and 215:
Page 216 and 217:
Index ■Numbers 2.4GHz to 928MHz b
Page 218 and 219:
asic access and best-effort deliver
Page 220 and 221:
■D dark fiber, features of, 75-76
Page 222 and 223:
harmonics, impact on AC power, 188
Page 224 and 225:
challenges to, 85-86 and NLOS, 121
Page 226 and 227:
PONs (passive optical networks), fe
Page 228 and 229:
signal diversity, providing with ad
Page 230 and 231:
■V VDSL and entertainment service
Page 233:
forums.apress.com FOR PROFESSIONALS
show all

WiMax Operator's Manual

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?