1. Chapter 7- Mobile and Wi-Fi Networks Taking signals on and off the air Connections to other networks Need to manage spectrum Managing and billing for services Connections to: voice mail, collaboration, instant messaging

2. Taking Signals on and off Airwaves Cellular base stations Base station & antenna Compatibility with Air interfaces – LTE, 3G Translates air interfaces to landline protocols & vice versa Connections to mobile core wired or microwave backhaul Wi-Fi access points Access point & antenna Compatibility with 802.11a,b,c n and other Wi-Fi protocols Translates Wi-Fi protocols to Ethernet LAN protocols & vice versa Wired connection to LAN backbone Security functions

3. Fourth Generation Architecture Long Term Evolution (LTE) EnodeB SGW*MME* PGW* * SGW – Serving gateway * MME – Mobility management entity * PGW – Packet data network gateway Bearer channels for user data Signaling channels Evolved packet core Radio access network LTE Modified for data All IP 30 to 40% more capacity

4. Core, Base Stations and Increasing Capacity Functions in the core – Databases for: roaming, billing, voice mail – Security – Signaling – Connections to other mobile networks, the PSTN and the Internet – Keeping track of traffic & congestion – Balancing traffic between base stations if there's congestion Adding capacity – Add more cell sites – Upgrade to higher, newer protocols – 3G & 4G – Add more powerful orthogonal frequency division multiplexing (OFDM) antennas Functions in base stations – Translating between the radio frequency wireless signals and the wireline backhaul network – Connections to the backhaul network

5. Aggregation & Access in Backhaul Networks Aggregation network Core network Controllers for 2 nd, 3 rd and 4 th generation services at the edge of the core. 4 th generation security, other services and connections to the Internet & public switched network in the core. Access Networks Backhaul consists of access and aggregation networks

6. Spectrum What is it? Wavelength – Low frequencies - longer wavelengths – Higher frequencies - shorter wavelengths Lower frequency wavelengths Higher frequency wavelengths

7. Pre – 4 th Generation Air Interfaces AT&T & T-Mobile – HSPA+ (High speed packet access plus) – AT&T installing LTE Verizon, Sprint, China Mobile & MetroPCS – LTE – TD-LTE (China Mobile trialing) Sprint Nextel – Changing from WiMAX to TD-LTE What is the impact of 4G on Internet access? In two or three years 4G will reach speeds of 100 Mb per second.

8. Mobile devices - Multimode versus Multi-band Multi-mode on the same device – WCDMA – GSM – LTE Multi-band on the same device – 700 megahertz (MHz) & 1.8 gigahertz (GHz) – 2.4 GHz & 5 GHz Wi-Fi

9. What is Wi-Fi? A wireless 802.11 Ethernet standard – Wi-Fi (Wireless fidelity) certification Why standards matter The downside of standards

10. Portability in Enterprises  Laptops & tablet computers  Cabling costs  Moves adds and change savings  Need for computers in common areas  Monitoring inventory and patients in hospitals I know where the beds are.

11. Key 802.11 Standards 802.11n Range Capacity Speed - 100 Mbps Why these matter MIMO multiple input/multiple output Multiple antennas Multiple streams of traffic

12. Security What can go wrong? – Complexity vs. ease of administration Intrusion detection – To detect unauthorized users – Shared passwords WPA2 (Wi-Fi Protected Access 2) 802.11i subset of 802.11i – AES (Advanced Encryption Standard) – 128 bit level of encryption - more sophisticated algorithm AAA authentication, authorization and accounting for remote user access Security appliances with advanced capabilities

13. 802.11 Infrastructure Wireless controller

14. Managing Wireless Local Area Networks (WLANs) Cincinnati Headquarters or the cloud Miami Kansas City Dallas Management console Statistics on usage Information on congestion Reports on security Identities of allowed users

15. Mobile Services Summary Wi-Fi and LTE architecture Key aspects of 4 th generation LTE Service – IP protocols – LTE – More capacity on Backhaul Spectrum Handhelds & user experiences Enterprise Wi-Fi networks Key Wi-Fi standards – 802.11b, g & a and n – Improved antennas - MIMO Security Access points