The Cast Devices Home-Mobile Desktop Computer Mostly data Wired network Standard Telephone Mostly voice Wired phone line CCST9015 6th Oct, 2010 Dr. Hayden Kwok-Hay So Notebook Computer Mostly data Wireless network (WiFi) Mobile Mobile phone Mostly voice Mobile network (GSM) Department of Electrical and Electronic Engineering The Cast Network Related 2 The Cast Network Related (2) GSM (voice) (data) Backhaul Link Optic Fibre Connect to other cell towers Cell tower Connects to all MS GSM, Wired Phone network WiFi network Wired Phone network Wired network (ethernet) DSL Wired network (ethernet) Route data through phone network Hotspot/ Home Router Share/route data traffic to the 3 4 Voice over IP (VoIP) Transmit voice over IP network Transmit phone calls over the 5 1
VoIP vs. Traditional Voice Services Voice conversation transmitted as analog signal VoIP vs. Traditional Voice Services Quality guaranteed with circuit switch technology Voice conversation transmitted as packetized data Quality fluctuate with packet switch technology Good The use of IP network allows it to operate with any connection Make phone calls anywhere with internet connection Bad Voice quality NOT guaranteed A common problem with packet switch network Need sophisticated quality of service (QoS) technology built in Even more difficult with multiple users 7 Example: VoIP and iphone Emergency services (location awareness) 8 New challenges from VoIP International direct calls (IDD) sales connection is not guaranteed IP network is everywhere, no need for IDDs Urgent calls? Emergency calls? Emergency services cannot locate the source of a call Easier to eavesdrops than traditional phone calls? Phone call as utility? With direct access, it s possible to create a VoIP App Official Skype App is FREE on official App Store Initially restricted to use WiFi connection only Recall the discussions on service as a utility NOT 3G network! 10 A TV Commercial in May 2009 11 2
So What is It? Typical Connection Shared use at home One sleek box gets you online with Wi-Fi and up to 4 cable connections. Our box is an all-inone modem and router for broadband access for your whole family. It comes with a telephone service. Connect your existing phone with either a new telephone number or switch your current number to us. Apply 001 IDD for everyday low rates! Detail Connections WiFi connection 54 Mbps (802.11g) Standard Phone line Ethernet Connection 100 Mbps Detail Connections Connection 3G network 7.2 Mbps down 2 Mbps up RNC UTRAN MSC Landline Switch DSLAM Cell Tower ADSL INDOOR 3
Phone Connection Making Phone Calls RNC UTRAN MSC Landline ADSL Switch Is it a cell phone call, land line call, Voice over IP (VoIP) call? DSLAM What telephone number do you get? INDOOR Cost? In Comparison Item S-V Home Broadband Major Landline Provider Monthly Fee (Phone) 0 110 Monthly Fee ( Access) 148 294 Call Waiting, Forward 0 29 Source: http://www.smartone-vodafone.com/jsp/mobile/home_broadband/english/price.jsp 2009/09/22 Other Considerations TV services Combined service promotion Existing landline number Emergency Calls Privacy Landline Mobile Phone Access Multimedia (TV) Mobile WiFi hotspots Existing contracts 24 4
Conventional WiFi Connection at Home Cutting the Wires ADSL WiFi connection used to connect notebook computers/mobile phone with a home router The home router relays data connection to the through a DSL modem and phone line/ cable Similar connection in WiFi hotspots 25 Shrinking the Router What if we can replace the wired Ethernet connection with a 3.5G HSPA connection? All traffic can be routed through the mobile phone network No more wired connection 26 Mobile WiFi Many existing mobile devices do not have HSPA (3G) (data) connection capabilities Mobile WiFi allows any device with commodity WiFi connection to connect to the with mobility E.g. Laptop computer, Netbook With a reduced size, and no wired connection, it is then possible to bring this router onto the street In fact, multiple devices may access concurrently A mobile router But Why? 27 Business considerations WiFi equipments are cheaper than HSPA equipments Each HSPA-capable device must have its own SIM card (phone number) 28 Business considerations Most importantly business considerations ($) Which kind of industry will like this mobile technology most? Many more types of devices supported Fixed phone line company Mobile phone company service provider Mobile device maker Mobile service provider E.g. 4 accounts at mobile phone company vs 1 29 30 5
Who Offers Mobile Access Services in HK? PCCW Netvigator An ISP Part of PCCW Offers both router (2 or 5 devices) and USB modem (1 device) version of mobile access 3 Hong Kong (Mainly) Mobile phone service provider Offers USB modem One two free (Mainly) Mobile phone service provider Offers USB modem A mobile phone service provider Offers both router and USB modem Smartone-Vodafone 31 Introduction to Femtocell A technology that places a (mini) base station in your home Mobile devices connect to a femtocell base station is exactly the same as connecting to a standard macrocell base station 32 Conceptual connections GSM Without femtocell Your private cell tower Phone Network/ 33 Motivations for Femtocell Drawbacks Better reception indoor Same mobile device indoor and outdoor No need to support multiple standards on the same mobile device Cost: Recall the benefit of a cellular network over the old non-cellular network Support more user on the same mobile network 34 Requires multiple SIM card accounts Requires a link from femtocell to the main cell tower infrastructure Make use of existing connection at home Rebroadcast the signal with higher strength to another tower Dedicated connection to other cell tower Increase mobile phone network capacity With femtocell = cost WiFi only < HSPA only < WiFi + HSPA DSL 35 36 6
Technical considerations Interference with other cell tower in range Recall that radio spectrum is licensed, with extremely high price A cell tower should only transmit in certain geographical location What happens when the femtocell is moved around? Handover problem when a user moves from indoor to outdoor The femtocell must be able to contact the larger outdoor macrocell Need sophisticated technology to determine the location of the nearest macrocell BS for handover GPS + signal strength estimation Who is offering femtocell in HK? Not on the market yet Considered by major mobile phone providers Some success outside Hong Kong Especially in places where indoor coverage is difficult with macrocell 37 38 In conclusion Advance technology has blurred the distinction between Voice vs data connection Indoor vs outdoor Mobile vs fixed The changes have longterm implication to existing business model Fixed-line phone service provider service provider Mobile phone service provider Content provider Practical consideration for users: Cost Lock to company Emergency service Location based service Regulatory considerations: Licensing terms for existing business model no longer applies The concept of utility Spectrum allocation 39