Telecom Regulatory Authority Technical Affairs & Technology Dept. Mobile Internet Via Satellite

Transcription

1 Telecom Regulatory Authority Technical Affairs & Technology Dept. Mobile Internet Via Satellite September, 2003

2 Index Executive summary Introduction System Description Space segment Ground segment Business segment User segment Interconnection between GPRS network and internet Aim of the shared infrastructure scenario Description Modulation and Coding: Effective data rate Coverage Regional BGAN system coverage B-GAN system coverage Satellites' Frequency Spectrum R-BGAN BGAN: Migration strategy Services Service access Billing System interfaces Communication interfaces Management interfaces Numbering resources Emergency calls handling in R-BGAN and BGAN Fraud Management Conformity Assessment of BGAN mobile Satellite Units Interconnection and Interoperability Legal interception(li) of communications in BGAN Implementation of BGAN LI capability Interception of communications Practical aspects Products Regional BGAN products BGAN products BGAN portable products type Summary Conclusion Mobile Internet via Satellite 1

3 Executive summary In response to the request of Egyptian space company ESC to get a license to deliver Regional BGAN services in Egypt, we prepared a technical study to present different technology aspects of R-BGAN and BGAN systems, demonstrating the services delivered by R-BGAN, service access techniques, system architecture, coverage, frequency spectrum, billing, numbering and many other system features. R-BGAN stands for regional broadband global area network, this system is implemented by Inmarsat to provide IP connectivity to satellite subscribers to offer a commercial data-only service. It provides IP connectivity with a data rate up to 144 Kbps, ESC will be a Distribution Partner DP for Inmarsat to deliver RBGAN services in Egypt. R-BGAN provides the following services: and messaging, data file transfer, internet access, intranet access. In R-BGAN, users will be charged for packet data services based upon the amount of information sent and received rather than the time for which they are connected. R-BGAN coverage includes almost all of Europe, Northern and parts of Central Africa, central Asia, the middle east, and the Indian sub-continent. Space Segment Ground Segment SAS Italy GPRS Network BSS United Kingdom User Segment Terrestrial PDN SP POPs User Segment To achieve IP connectivity in R-BGAN, Inmarsat implements Satellite Access System SAS in Italy. SAS contains receiving systems and GPRS network owned by Inmarsat to offer the connectivity to ISPs for internet cloud access, this acts as a gateway between satellite users and Internet data network. R-BGAN users can interface with satellite through mobile satellite unit MSU which consists of laptop or PC and a satellite modem. On the other hand, service provider point Mobile Internet via Satellite 2

4 of presence SP PoP interfaces Inmarsat GPRS terrestrial network SAS with internet. Both MSU and SP PoP form the User Segment. For the provision of R-BGAN, the satellite resource capacity is leased by Inmarsat from the geostationary(geo) spacecraft of the Thuraya regional system, this forms the Space Segment. For the provision of management functions, Inmarsat implemented business support system BSS in UK, this system provides functions required to support products and services, billing, customer care, revenue collection, fault management, system provisioning, customer management, and interconnect billing system. All billing and management information are collected in the BSS, in UK. BSS forms the business segment in R-BGAN. R-BGAN uses FDMA and TDMA. The frequency spectrum in R-BGAN is divided into sub-bands, each sub-band is mapped to a specific spot beams. Each sub-band is divided into a number of frequency channels, and each cannel is divided into timeslots according to a periodic frame pattern, left handed circular polarization, LHCP, used in R-BGAN. Users transmit and receive in L- band, while SAS transmits and receives in C-band. At the end of the report, we mention some points that can be taken into consideration when issuing this license as a conclusion. Mobile Internet via Satellite 3

5 1 Introduction Inmarsat LC is an independent private company that operates a global satellite system used by independent service providers to offer voice and multimedia communications for customers on the move or in remote locations. The predecessor of the company was established in 1979 as a multi-national organization under the auspices of the United Nations, to serve the maritime industry by developing and operating a satellite communication system for communications and distress/safety functions for ships at sea. Inmarsat has since expanded its service offerings to include voice, fax and data services for terrestrial and aeronautical users as well. Inmarsat is currently developing its next generation mobile satellite communication system, termed Broadband Global Area Network (B-GAN). B-GAN technical characteristics of the system will be compliant with the GMPCS MoU. B-GAN is intended to be part of the satellites component of the third generation (3G) IMT- 2000/UMTS. Inmarsat will retain management and operational control of the space segment and will own and operate the ground stations. B-GAN provides high-speed packet and circuit-switched services to land mobile users. Inmarsat will implement the system in two phases, starting in late 2002 by the first phase, Regional B-GAN. Regional B-GAN system consists of a satellite-based communications platform providing IP connectivity to satellite subscribers to offer a commercial data-only service. From user perspective, B-GAN offers both symmetric and asymmetric services to and from a range of fixed and portable mobile satellite terminals. The system can also take advantage of Bluetooth technology allowing wireless connectivity between satellite modem terminal and a whole range of standard computing devices such as notebook computers, laptops, personal digital assistants and other mobile devices. Mobile Internet via Satellite 4

6 The following table illustrates the main features of the Regional B-GAN and the B-GAN systems: Characteristic Regional B-GAN B-GAN Orbit GEO GEO Orbit location 44 East 65 East(IOR), 54 West(AOR) Number of (Capacity leased from the 3 (2 + 1 ground spare) satellites Thuraya satellite) Satellite Launch Late-2000 Planned end 2004 date Mobile Link L band L band Frequency Band Geographic coverage Regional (Thuraya satellite footprint) includes almost all of Europe, Northern and parts of Central Africa, Central Asia, the Middle East, and the Indian sub-continent. Approximately 70% of total geographic areas which coincides with 80% of landmass covered by Inmarsat-3. Type of coverage Spot beam Global, wide and narrow spot beam Satellite payload type Forward Link Return Link L-Band Polarization C L band: Forward Link (SAS to UT). L C band: Return Link (UT to SAS). C C band: Cross Link for timing and synchronization. Receives transmissions from each SAS in the bans MHz. Transmits to the UTs in the band MHz. Transmits to the SAS in the band MHz. Receives transmissions from UTs in the band MHz. Left - Handed Circular Polarization (LHCP) C L band: Forward Link (SAS to UT). L C band: Return Link (UT to SAS) C C band: Cross Link for timing and synchronization. UT UT band: Cross-Link (not currently implemented by Inmarsat) Receives transmission from the SASs in the band MHz. Transmits to the UTs in the band MHz. Transmits to the SAS in the band MHz. Receives transmissions from UTs in the band MHz. Right - Handed Circular Polarization (RHCP) Mobile Internet via Satellite 5

7 Service launch date Number of satellite access nodes Number of connections to other networks (SPs POPs) Total bandwidth/channel November ( in Fucino Italy) 4 Nodes (locations to decided) 20 initially at regional gateway Up to KHz Able to support multiple UTs and multiple call sessions on the same channel Initially up to 30 from each of the 4 logical SAS Up to 190 KHz Able to support multiple UTs and multiple call sessions on the same channel Data Rate Up to 144 Kbps Up to 432 Kbps Applications 1. and messaging 2. Data file transfer 3. Internet access 4. Intranet access Table 1:Comparison between the R-BGAN and BGAN Systems 1. and messaging 2. Data file transfer 3. Internet access 4. Intranet access 5. Remote LAN access 6. Remote database access 7. Video conferencing 8. Telephony 2 System Description The Regional B-GAN system is an integrated communications system that is composed of four segments: 1. Space Segment, 2. Ground Segment, 3. Business Segment and, 4. User Segment. 2.1 Space segment The Space Segment consists of the satellite recourses leased by Inmarsat from the Geostationary (GEO) spacecraft of the Thuraya regional system. Mobile Internet via Satellite 6

8 2.2 Ground segment The Ground Segment allows the transport of information between satellite users and the terrestrial networks providing these services. The ground network architecture is an extension of the General Packet Radio Service (GPRS) cellular data communications system. The ground segment consists of a single site where the Satellite Access Station (SAS) resides, in Fucino, Italy. The B-GAN system comprises the ground segment gateways that provide connectivity to and from the external networks, notably PSTN, ISDN, and IP PDNs and business support infrastructure. In the BGAN system, 4 SASs will be implemented at different geographical locations. In the new ground segment, each SAS will provide the necessary connectivity to deliver a new generation of services over a variety of external networks to B-GAN users. In R-BGAN, Inmarsat has implemented its own GPRS network. The GPRS infrastructure(i.e. the GPRS node, etc ) is part of the SAS located in Fucino,Italy. In R-BGAN, the SAS consists of three main subsystems: o The Packet Base Station Subsystem (PBSS): The PBSS is responsible for providing and managing the transmission paths (radio interfaces) between the user terminals (UTs) and the SAS network equipments. o The Network Switching Subsystem (NSS): The GPRS cellular data communication system performs the NSS functions. The GPRS system provides a basic solution for Internet Protocol (IP) communication between user terminals and internet service host. GPRS is an extension of the GSM architecture. The voice data traffic runs on the GSM backbone, while the packet data traffic runs on the following backbone IP network: Serving GPRS Support Node (SGSN): The SGSN provides packet routing to and from an SGSN service area. It performs functions such as routing, security, mobility management, authentication, session management and charging functions. Gateway GPRS Support Node (GGSN): The GGSN provides the interface towards both other networks and the external IP networks. It performs the functions of routing, firewall, border Mobile Internet via Satellite 7

9 gateway, security, mobility management, session management and charging functions. The SGSN and GGSN are routers that support mobility of terminals Home Location Register (HLR): The HLR is responsible for the database functions and the call handling functions. It performs functions such as location updating, Authentication of data request fault, basic administration of subscriber data and administration of roaming area characteristics. o The Data Communications Network (DCN): The DCN provides the IP connectivity to the Regional B-GAN site, in both the Ground and Business segments. The DCN includes also the equipment that supports the access links between the SAS and POPs. The DCN also includes security (firewalls) to protect the Regional B-GAN network from the external networks to which it is connected. In BGAN, Inmarsat will have its own UMTS core network infrastructure, just as any other UMTS infrastructure. This includes SGSN and GGSN and nodes, voice media gateways, home location register for subscriber authentication, authorization and location information, etc. 2.3 Business segment The Business Segment consists of the Business Support System (BSS), which provides the management functions required to support products and services. These functions are billing, customer care, revenue collection, fault management, system provisioning, customer management, and interconnect billing system. The BSS supports three external interfaces: o BSS Service Provider: handles the interface function to the Service Provider. o SAS Billing Operations center: interacts directly with two GPRS network components: Billing Gateway (BGw) Service Order Gateway (SOGw). Via this interface, the BSS receives information about faults and/or shortages of the network from the Network Management System (NMS). This information covers radio components (radio congestion, fault of radio equipment) as well as the network (e.g. DCN congestion, GSN/HLR faults) Mobile Internet via Satellite 8

10 o BSS Operation and support system 2.4 User segment The User Segment carries the function to interface satellite and terrestrial users to the Regional B-GAN system. The User Segment consists of the following elements: o User Terminal or Mobile Satellite Unit (MSU) that will consist of Lap top or PC and a satellite modem terminal that connects the end user computing equipment to the satellite network. Additionally, the MSU retains the capability to access the GPS constellation in order to determine its position on the earth. The MSU will enable the user to link the satellite modem with its PC via different wire line and wireless interfaces, such as Universal Serial Bus (USB), Ethernet, and Bluetooth. In order for the user to access the data service, a valid SIM (in case of regional B-GAN) or USIM (in case of B-GAN) card must be inserted in the user terminal, and a service profile must exist in the network. For BGAN, the system design supports three different classes of Land Portable User Terminal Equipment. Each UT class is required to support a range of different bearer types to provide the BGAN radio resource management sufficient flexibility to support different numbers of each UT class in any spot beam with good bandwidth and power efficiency. For the purpose of this document the UT is analogous to the UMTS mobile terminal (MT). The uplink and downlink rates vary according to the type of BGAN terminal; the following data rate ranges are associated to each type of terminal: Technical Feature BGAN Briefcase/A3 MSU Portable Class1 BGAN Notebook/A4 MSU Portable Class2 BGAN Pocket/A5 MSU Portable Class3 Transmission Rate Kbps receive Kbps transmit - With dynamically variable bandwidth allocation in each direction Kbps receive Kbps transmit, - With dynamically variable bandwidth allocation in each direction Kbps receive - 72 Kbps transmit - With dynamically variable bandwidth allocation in each direction. The MSU in the B-GAN system will present these extra capabilities: To access the wider range of third generation (3G) data, voice and multimedia services. Mobile Internet via Satellite 9

11 To compatible with wider range of computing devices as the PDAs, UMTS products and Voice handsets To link the satellite with devices via more standard interfaces as the ISDN. o Service Provider Point of Presence (SP POP) that provides access to the terrestrial packet data (GPRS) network or to Internet Service Provider (ISP) User Link L Band Feeder Link C Band Return Forward SAS GPRS Network SGSN HLR GGSN Other PLMN Application Server ISP IP Network SP POPs Figure 1: R-BGAN Network Mobile Internet via Satellite 10

12 I4 Satellite (F2 ~ 54W) I4 Satellite (F1 ~ 65E) L-Band User Links L-Band User Links RF/IF RAN 1 RF/IF RAN 2 RF/IF RAN 1 RF/IF RAN 2 CN CN BGAN SAS 1 Satellite orbital Data; TT&C Inmarsat SCC BGAN DCN Resource & Network Management Inmarsat NOC BGAN SAS 2 Inmarsat BOC Billing Data, Fault Management, Customer care POP PDN PSTN ISDN Other PLMN Figure 2: BGAN Ground Network Architecture Mobile Internet via Satellite 11

13 2.5 Interconnection between GPRS network and internet Inmarsat offers a number of different interconnect scenarios that enable a DP like ESC to provide the full set of features and connectivity services that are available over the Regional BGAN network to their customers. The following sections describe the method of interconnect chosen by ESC, named Shared Infrastructure. Figure 3:high level overview Aim of the shared infrastructure scenario The aim of this scenario is to provide a quick, easy and cost effective means for DP s like ESC that want minimal involvement with the technical aspects of providing their customers with the Regional BGAN service. The main features of this solution are: There is no capital investment required by the ESC to run a service using this means of connectivity No IP PoP interconnect expertise is required by ESC to get started Inmarsat maintain and operate the end-to-end service Mobile Internet via Satellite 12

14 Additional connectivity services can be added and managed on their behalf Access to free managed interconnect service Access to unlimited private IP addresses Access to a limited number of dynamic and static public IP addresses for system evaluation Description The shared infrastructure scenario is essentially a managed service that provides DP s that either have no infrastructure of their own or do not wish to use existing infrastructure with a service that delivers their customer s traffic straight to the Internet. This scenario will utilise a predefined Access Point Name (APN) to allow ESC s customers to connect to the network. All ESC s customers that have opted to utilise this scenario share these APNs. ESC may also opt to purchase dedicated APNs for their shared infrastructure service. Dedicated APNs will incur additional Operational and Capital expenditure over and above the basic shared infrastructure charge. A dedicated APN will be required in order to reserve a guaranteed number of public IP addresses for ESC. Inmarsat provides a resilient interconnect to the Internet via diverse routing to two separate Internet Exchange Points in Italy. The network backbone Inmarsat is connecting to is called Seabone, and is run by Telecom Italia Sparcle, an affiliated of Telecom Italia (TI), one of the Inmarsat Regional BGAN Distribution Partners. Inmarsat currently connects to the backbone via two different TI Sparcle PoPs in Italy, one in Milan and one in Palermo, via diverse routing. User traffic is passed through these points onto the Internet. All ESC s customers that have opted to utilise this scenario share this local loop connection to the Internet. This is similar to services offered by standard ISP s. Inmarsat will monitor the utilisation of this connection and will increase the capacity as and when required. Once the user has activated a session and has been allocated an IP address they have direct access via the Internet to access the desired IP service. To meet ESC customers further requirements there is the ability for additional services to be added to enhance this scenario, however these will be subject to commercial discussion as they incur additional Operational and Capital expenditure. In order to ensure the implementation of the shared infrastructure connectivity by ESC, Inmarsat has implemented a resilient interconnect through the use of guaranteed dedicated leased lines that provide a link to the Internet international Point of Presence (PoP). Mobile Internet via Satellite 13

15 2.6 Modulation and Coding: For Regional BGAN, the following table summarizes the modulation and coding parameters: Regional BGBAN Terminal Characteristics Modulation Pi/4-CQPSK Coding Convolutional Coding r = ½, 5/8, 3/4 For BGAN the following table summarizes the type of modulation used by the different terminals: BGAN Product Types Modulation (Forward/ Return) Coding Briefcase 16QAM/16QAM TURBO Notebook 16QAM/16QAM TURBO Pocket 16QAM/0-QPSK TURBO 2.7 Effective data rate In Regional BGAN, each subband, carrying up to 144 Kbps uplink and downlink, is shared amongst a number of end users. he actual or effective data rate depends on: 1 The number of users located in the same spot beam. 2 The type of application used. 3 The number of carriers allocated to each spot beam. A predefined subband allocation based on traffic forecasts in addition to a sophisticated radio resource management system allocating capacity on demand allow to optimize resource utilization and to maximize the data rate available to each end user under the variables above-mentioned. Similarly in the BGAN system, the effective data rate available to the end user, that varies according to the type of product, each supporting different data rates, depends on the same three parameters. Mobile Internet via Satellite 14

16 3 Coverage 3.1 Regional BGAN system coverage The Thuraya satellite provides coverage with a multiplicity of overlapping spot beams. The use of spot beams provides the satellite antenna gain necessary to permit the operation of satellite mobile terminals with relatively low power and small antennas. In addition, the use of spot beams provides for the reuse of the L-band spectrum. The footprint consists of 296 spot beams. In Regional BGAN, in order to guarantee the user data rate of up to 144 Kbps the system relies on narrow beams only. Figure 4: R-BGAN Coverage Map 3.2 B-GAN system coverage The BGAN satellite coverage area will cover approximately 70% of the total geographical areas of the planet, this area will be serviced by three types of spot beams: a. 200 narrow spot beams that will cover a significant area of continental landmass within the satellite field of view. b. 19 wide spot beams that will cover the entire satellite fields of view for existing Inmarsat services. c. 1 global beam per satellite, which correspond to the coverage of each of the two satellites to be launched and deployed at Inmarsat existing IOR Mobile Internet via Satellite 15

17 orbit location (around 65 degrees East) and AOR-West (around 54 degrees West) orbit locations, with a third satellite currently being planned as a ground spare. In BGAN the provision of services to the user is achieved through a mixed use of wide and narrow beams. In general, narrow beams are utilized to support communications by end users. However for specific functions or circumstances such as for example call set-up or low traffic patterns respectively, wide beams are utilized by the system. Consequently, the utilization of wide and narrow beams within the global coverage of the BGAN system is not location-dependent. Satellite Overall Coverage Area AORW IOR Figure 5: BGAN Coverage Map Figure 6: BGAN Coverage Map for each Satellite Mobile Internet via Satellite 16

18 4 Satellites' Frequency Spectrum 4.1 R-BGAN The frequency band of the Regional B-GAN is divided into sub-bands. Each communication sub-band is mapped to a specific spot beams. Each sub-band is divided into a number of frequency channels, and each channel is divided into timeslots according to a periodic framing pattern. For a user to transport his/her IP packets through the satellite, a particular frequency channel (FDMA) and time slot/slots (TDMA) should be assigned to him/her to access the satellite service and transport his/her data. The number of sub-bands and the frequency of each sub-band depend on a number of factors such as: a. Traffic demands in the particular spot beam. b. Frequency reuse considerations. c. The effective spectrum available as a result of coordination with other systems, and the terms of leasing agreement between Thuraya and Inmarsat. 4.2 BGAN: The B-GAN satellite will use FDM/TDM radio access and signaling bearer technology using efficient higher order modulation and advanced coding schemes that can support the packet and circuit-switched services. Therefore, interoperability with existing 2G, 2G, 3G networks as well as established PSTN and ISDN fixed terrestrial networks will be achieved. The frequency spectrum of the satellite is reused at different apart spot beams to use lesser total bandwidth with minimum interference that give an accepted quality of service. The B-GAN system will achieve 20 times frequency reuse at the L-Band. Communications resources are assigned to the spot beams using transponders sub-bands, with an effective bandwidth of khz in the Regional B-GAN system and 190 khz in the B-GAN system. The I4 satellites integrate a more flexible satellite resource allocation system designed to support the wider range of BGAN services. The I4 satellite supports 630 channels that will be allocated between Inmarsat existing, Regional BGAN and BGAN services according to continuously evolving traffic demand. Mobile Internet via Satellite 17

19 5 Migration strategy With respect to the initial phase, the deployment of B-GAN will include: New Space Segment Expanded ground network Evolved User Segment with a multiplicity of terminal types in addition to those available in the first phase. To migrate from the Regional B-GAN to the B-GAN systems the following plan will be followed: The expiry of the lease of the Thuraya Space Segment and its replacement with the new B-GAN Space Segment over Inmarsat 4 satellites. Transitioning of the satellite subscribers from Regional B-GAN to B-GAN. The Regional B-GAN SAS implemented in Fucino, Italy, might be configured to form a part of the B-GAN system. 6 Services In the regional B-GAN, the ground network architecture is an extension of the General Packet Radio Service (GPRS) that aims to support packet data connectivity with internet users. Consequently, packet data capability only is provided to end users. The service provider (SP) will connect into satellite access station (SAS). This means the SP will act as the point of presence (PoP) for incoming/outgoing internet traffic. The outward connections from the PoP to internet service hosts will be established by the service provider. It is via these hosts that internet services will be supported. The internet hosts will support facilities such as World Wide Web (WWW) servers, domain name service (DNS), , etc. The GPRS packet data supported by Regional B-GAN are: 1. and messaging 2. Data file transfer 3. Internet access 4. Intranet access Mobile Internet via Satellite 18

20 With the full implementation of B-GAN other packet data applications will be supported as: 1 Remote LAN Access (e.g. Windows Dial-up Networking). 2 File Transfer (e.g. FTP, HTTP). 3 (e.g. Internet web-based using POP3/SMTP, IMAP4 access over TCP/IP to an Internet mail server, etc.). 4 Simple Text Messages (e.g. chat IP based applications). 5 Internet Browsing (e.g. HTTP for WWW browsing, WAP for mobile browsing). 6 Remote Database Access. 7 Video Conferencing (e.g. NetMeeting). 8 Telephony. In addition, service inter-working will be supported as well as PSTN access for telephony and for data, ISDN access for telephony and for data (including corporate network access), PDN, other PLMNs (i.e., GPRS networks), in line with third generation (3G) IMT-2000/UMTS developments 7 Service access To enable the user to start an application, the system performs the following main actions: 1. GPRS attach. 2. Location update. 3. Sub data insertion by the VLR. 4. IP session (also referred to as PDP text activation). 5. Start the application. These actions are not specific to the satellite environment; rather they are the prerogative of the standard GPRS environment. Satellite modem operates either in three modes: a. Idle b. Standby c. Ready Satellite users require the following to have a R-BGAN/BGAN connection: a. Mobile satellite unit, MSU. b. Subscription. c. Activation of this subscription with an Inmarsat provider. Mobile Internet via Satellite 19

21 d. The user may require the activation with the private internet service provider independently of the subscription to the Regional B-GAN satellite system. For the end user to have an access to the Regional B-GAN services, he/she will pass through the following steps: 1. The satellite user must power-on the mobile satellite unit and point its antenna assisted by pointing routine. This routine guarantees optimum access to the satellite service from the user location. 2. The MSU registers with the system through its international mobile subscriber identity (IMSI). During this operation, called GPRS Attach, the network checks if the subscriber is authorized and registers his location. Once the subscriber is attached, the system keeps track of the satellite user location within the coverage area of the satellite. 3. For the user to gain access to regional B-GAN packet data services, a so-called IP session needs to be activated so that the routing of information between the user unit and the external terrestrial network can take place. With the IP session, the system assigns the MSU an IP address, the required protocol configuration and characteristics of the service. 4. Once the IP session has been established, the application can be started. The MSU may send and receive data to the terrestrial network. The disconnection of users from the regional B-GAN network is done according to the detach procedure which may be initiated by the mobile satellite terminal or the system itself. Mobile Internet via Satellite 20

22 1. MSU Power-On 4. PDP Context Activation 2.a. MSU Registration Request SAS GPRS Network 2.b. MSU s Location? HLR IP Network ISP GGSN SGSN 3. MSU s Info. VLR 2.c. MSU s VLR 5. Application Start 2.d MSU Location Update? Figure 7: Steps of accessing the BGAN services Mobile Internet via Satellite 21

23 8 Billing Users will be charged for packet data services based upon the amount of information sent and received rather than the time for which they are connected. 9 System interfaces The main system interfaces to be implemented in the regional B-GAN system are not expected to differ significantly from those realized in B-GAN. In the regional BGAN communications architecture, two main types of interfaces are defined: Communications interfaces: which support the range of network and user information capabilities. Management interfaces which support the provisioning, operation and management of the regional BGAN system. 9.1 Communication interfaces The communication interface that interconnect the four functional segments of the system are the following: The SAS-to-satellite interface: this feeder link interfaces between the SAS and Thuraya space segment. The link operates at C band. MSU-to-satellite interface (AI): this interface enables the SAS and satellite users equipped with Regional B-GAN MSU to access packet services through the efficient use of the satellite resources. The PoP-to-terrestrial network interface: this interface provides access to the internet or private IP-based networks. external internet service providers(isps) such as terrestrial ISPs, cellular ISPs, content servers, and corporate networks connect their application servers to the regional BGAN architecture via the distribution partners to make their services available to the satellite users.inmarsat will operate as a wholesalers of airtime through which regional B-GAN services will be offered. The SAS-to-business support system (BSS) interface: over this interface, servicedriven information is exchanged such as call Data Records (CDRs). reports of major network alarms, and network performance reports. Mobile Internet via Satellite 22

24 9.2 Management interfaces The management interfaces are relevant with respect to the issue of the management of new customers, wholesale billing information, modification or deletion of subscription of existing customers, etc.. In Regional BGAN the provisioning of new customers is handled through the Billing Support System or BSS. Through the BSS all information and details related of a new subscriber can be exchanges between Inmarsat and the DP. 10 Numbering resources Each satellite terminal will have an unique network name for which the system will derive addresses on a dynamic or static allocation basis as appropriate. The identification, validation and authentication procedures for users will be based on the use of subscriber identification module(sim) cards inserted into the data-only terminals. Each SIM card will conform to GSM specifications and will carry its own unique identifier based on an ITU-T recommendation E.118, the issuer identification number(iin) associated with E.164 country code 870. The IIN is effectively the number of the integrated circuit card, which is the SIM card. In addition, the SIM will carry an international mobile subscriber identification (IMSI) in accordance with ITU-T recommendation E.212 incorporating Inmarsat own unique combination of mobile country code (MCC) and mobile network code (MNC). The use of the SIM card mechanism offers the potential of a migration path from the initial regional B-GAN service to the full complement of the B-GAN services. Inmarsat is in the process of applying for the numbering resources associated with the use of GSM style SIM cards for B-GAN. For applying for the numbering resources, the following will be submitted: Application to the ITU, via the UK administration, for Inmarsat own unique combination of mobile country code (MCC) and mobile network code (MNC). Application to the DTI/RA (with a registration fee payable to the ITU) for an IIN. Mobile Internet via Satellite 23

25 11 Emergency calls handling in R-BGAN and BGAN An increasing number of countries worldwide set out in their telecommunications legislation a licensing or operational requirement to provide emergency call handling. Traditionally, the requirement to handle emergency calls has been associated with the provision of circuit-switched public telephone service. This aspect is significant,as R- BGAN will be characterized by the provision of data-only services, no voice element will be present, consequently, no issues about emergency calls handling are expected to arise. However, the B-GAN system will provide a much wider range of services including voice. This aspect potentially, gives rise to a requirement for emergency call handling. In this respect, it must be stressed that the nature of emergency call handling may have to be customized to each country s requirements. The satellite terminal on a national territory to be able to make emergency calls to a designated national emergency callhandling centre, this in turn requires that the satellite service provider be given a single international format telephone number to which emergency calls may be directed from BGAN land mobile terminals. At the emergency call handling centre, calls are normally processed through a human interface. This concept presents an advantage in that a standard approach can be developed regardless of whether or not the satellite system has any location determination capability. 12 Fraud Management The B-GAN system can be used illegally by fraudulent by the following three scenarios: I. An end user in possession of a BGAN terminal tries to access the satellite service in a country where the commercial provision of a BGAN service has not been duly authorized by the National Regulatory Authority. In this case, the attempt to gain access is dealt with in the system at the network level. In -GAN, the implementation of position reporting capabilities means that on the basis of specific requests by the National Authorities the system can use look-up tables in order for the network to deny access to a user whose position is determined to be within a jurisdiction where BGAN services are not authorized. II. The second scenario concerns a country where the service can be legally allowed but a specific service provider does not hold the required authorization. BGAN system doesn't discriminate between authorized and unauthorized providers, but Inmarsat can terminate the provision of unlicensed service by deactivation of the SIM card to users on basis of the subscriber's identity Mobile Internet via Satellite 24

26 information provided by the country's National Authority Agent and/or the Law Enforcement Agency. III. The third scenario occurs when access to the satellite network is sought after by people who are not customers to the BGAN system. This scenario is dealt with by the BSS Fraud management subsystem where, fraud detection will be conducted at both the network and subscriber level. Using authentication methods and public key encryption prevents usage of the network by persons who are not customers of the system. On the subscriber level, the system will carry out analysis of technical fraud such as cloning, fraudulent usage patterns, velocity checks, credit balance monitoring, multiple call forwarding, and multiple simultaneous cards amongst others. Mobile Internet via Satellite 25

27 13 Conformity Assessment of BGAN mobile Satellite Units All user terminals types should be type approved that leads to have the permission to carry the CE marking on the terminals. In order to obtain CE approval, the MSUs will comply with following 3 types of essential requirements: 1. Effective use of the radio spectrum and orbital resources, including Electromagnetic Interference (EMI). 2. Electromagnetic Compatibility (EMC) 3. Safety The following set of standards may be considered applicable to the MSUs 1. EMI Standards o ETSI EN v1.2.1 Satellite Earth Stations and Systems (SES); Harmonized EN for Mobile Earth Stations (MESs) of Geostationary mobile satellite systems, including handheld earth stations, for Satellite Personal Communications Networks (S-PCN) in the1,5/ 1,6 GHz bands under the Mobile Satellite Services (MSS) covering essential requirement under Article 3.2 of the R&TTE Directive. o ITU-R M.1480 Essential Technical requirements of mobile earth stations of geostationary mobile-satellite systems that are implementing the global mobile personal communications by satellite (GMPCS)- MoU arrangements. 2. EMC Standards o ETSI EN EMC and Radio spectrum matters (ERM); EMC standard for radio equipments and services; Part1; Common technical requirements. o ETSI EN EMC and Radio spectrum matters (ERM); EMC standard for radio equipments and services; Part 20; Specific conditions for MES used in the MSS. 3. Safety Standards (R&TT Directive Article 3.2) o CENELEC EN Safety of Information Technology Equipment. o IEEE c : IEEE Standard for the Safety Levels with respect to Human exposure to Radio Frequency Electromagnetic Fields, 3 khz to 300 GHz. Mobile Internet via Satellite 26

28 14 Interconnection and Interoperability With respect to the aspect of interconnection, the private Inmarsat GPRS network, located in Fucino, can support inbound roaming. In other words the system allows the utilisation by the user of other GSM and GPRS operators SIM cards with the Regional BGAN terminal. It must be stressed that the implementation of inbound roaming is in any case subject to prior conclusion of the required commercial roaming agreements between Inmarsat and other GSM/GPRS operators. Unlike in regional BGAN, when data-only service inter-working will be supported as well as PSTN access for telephony and for data, ISDN access for telephony and for data(including corporate network access),pdn,other PLMNs (i.e., GPRS networks),in line with third generation(3g) IMT-2000/UMTS developments. Mobile Internet via Satellite 27

29 15 Legal interception(li) of communications in BGAN Interception of communications is generally defined as the simultaneous gathering of data and information as they are created during a communication. this includes information related to both: 1. Setup and delivery of communication(date, time and duration of an IP session or a call, dialing information etc) 2. Communication content(such as data, actual voice e.g. conversation or message,sms text etc.) Implementation of BGAN LI capability B-GAN system architecture will include the functionality required to perform the legal interception(li) of communications on behalf of a legally entitled authority, normally referred as a Law Enforcement Agency(LEA). The LI functionality will be provided starting from the initial implementation of B- GAN in late-2002,and no significant modifications will be required for the system full deployment in 2004,apart from the wider scope of interception capabilities to include voice and multimedia sessions. The key technical aspect to be underlined is that this LI functionality is implemented jointly with the position determination/reporting features. This is because in the satellite it is not sufficient to know the target s telecommunication identity. It is also necessary to validate the location of the target user to the requesting country. Consequently, GPS-enabled terminals will be used. It must be stressed that in B-GAN, the LI functionality is based on the ETSI-standard LI architecture whilst some adaptations are required for operating in AGPRS/UMTS satellite environment, the main components of the LI architecture conform to the standard. To enable proper supervision of the interception of communications, a central control facility will be located in the Network Operation Centre (NOC) at the Inmarsat headquarters in London, UK Interception of communications For the interception to take place, the LEA has to provide so-called target identification information to an interception management centre. In practice the LEA delivers a valid legal authority to the office in charge of managing the LI facility, whether it be an Inmarsat central or regional office, or the offices of an Inmarsat service provider Mobile Internet via Satellite 28

30 Since many national security authorities require that target identifying data be controlled within their jurisdiction, the B-GAN LI architecture includes a component designed to be managed locally, the remote provisioning unit (RPU). This unit makes it possible to input the information necessary for the interception of communications from the premises in a remote location. The RPU is a national facility, implemented and operated in a given jurisdiction in accordance with national regulations by either the Inmarsat national licensee(e.g. the service provider), the national LEA or its Designated Security Agency. Normally, the RPU will be located with the license-holder in each country; however, depending on local regulations on security, it could also be located with regulator, Law Enforcement or other Security Agency Practical aspects In the initial B-GAN implementation phase, data-only services will be provided to end-users, therefore the system will enable only the interception of IP traffic. The identification of IP packets to be intercepted occurs at the start of each session and the activation of the interception requires a multiple verification: 1. Existence of a parameter for the identification of targeted user. 2. The date of interception corresponds to that specified on the warrant. 3. The geo-location of the user terminal at the beginning of the session corresponds to service area and country code in the jurisdiction of the authority serving the warrant. The B-GAN LI system will be able to implement interception addressed by up to 200 monitoring centers, assuming one centre per country on average. Up to 5 RPUs per country can be connected to the system and up to 4000 concurrently active targets can be pursued. Mobile Internet via Satellite 29

31 16 Products It must be declared that all the B-GAN mobile satellite units which will be part of the portfolio of user products planned for regional B-GAN and B-GAN will have obtained all the declarations of conformity,conformity assessments, marks or other approvals required for their circulation Regional BGAN products In the regional B-GAN,the user data terminal is a mobile portable satellite modem that provides the end user computer equipment with network access via the space segment. User terminal looks and feels like a laptop, costs about $1100, receives and transmits at 144 kbps with enduser airtime charge around $11/MByte 16.2 BGAN products In B-GAN, it is planned that a range of standard and specially Mobile Satellite Unit (MSUs) will be produced to support the greater range of service offering. The B-GAN user segment will comprise three key logical elements: 1. The mobile satellite unit, satellite modem. 2. The end user device, which represent the interface through which the users access the satellite services. 3. UMTS subscriber identity module(usim),smart card that hold the subscriber identity, performs authentication algorithms. Physically the user device and the MSU may reside in the same or separate devices, while the SIM is normally to be located in the MSU. Mobile Internet via Satellite 30

32 A wide range of terminal types is under development: Handheld: recieves at 72 kbps and transmits at 16 kbps. Briefcase: recievs at 432 kbps and transmits at 432 kbps. Transportable: recieves at 1 Mbps and transmits at 1 Mbps Pocket User Terminal 800 grams 22 x 14 x 3 cm Receives at 216 kbps Transmits at 72 kbps Notebook User Terminal With detachable Remote Antenna Recieves at 432 kbps Transmits at 144 kbps Mobile Internet via Satellite 31

33 16.3 BGAN portable products type The B-GAN product range will have the following common operational features: 1. The MSU will require direct visibility to an inmarsat-4 satellites. 2. The MSU will operate indoors when positioned close to a window, with uncoated glass panes. interconnection to user devices will be via the supported interfaces( Bluetooth,USB, RS-232,Ethernet port). 3. The MSU will be designed to withstand industry standard environmental conditions and product variants specifically designed for harsher environmental conditions. There are three main B-GAN product types: 1. B-GAN notebook MSU portable: it satisfies the requirements of the primary B-GAN user, this product is targeted for use with laptop devices. 2. B-GAN pocket MSU portable: it is targeted for users who require a highly portable unit with medium data rate capability. B-GAN briefcase MSU portable: it is directed towards the need to provide a remote office/campus communications capability. Mobile Internet via Satellite 32

34 17 Summary Upon the request of the Egyptian Space Company (ESC) to get a license to provide R- BGAN service, this report is prepared to present a study about the technical specifications of the Regional BGAN and the BGAN Systems (the second phase of the R- BGAN system), that are developed by Inmarsat company. Regional B-GAN system consists of a satellite-based communications platform providing IP connectivity to satellite subscribers to offer a commercial data-only service. B-GAN provides high-speed packet and circuit-switched services to land mobile users. System structure: The R-BGAN system consists of 4 main segments: 1. Space Segment that consists of the satellite recourses leased by Inmarsat from the Geostationary (GEO) spacecraft of the Thuraya regional system. 2. Ground Segment that allows the transport of information between satellite users and the terrestrial networks. The ground segment consists of a single Satellite Access Station (SAS) (4 SASs in the BGAN system). The SAS consists of : Packet Base Station Subsystem that is responsible for providing and managing the radio interfaces between the User Terminals (UTs) and the SAS network equipments. Network Switching Subsystem which consist of the following GPRS components: a. Serving GPRS Support Node (SGSN) b. Gateway GPRS Support Node (GGSN) c. Home Location Register (HLR) Data Communications Network (DCN) that provides the IP connectivity to the Regional B-GAN site, in both the Ground and Business segments. 3. Business Segment consists of the Business Support System (BSS), which provides billing, customer care, revenue collection, fault management, system provisioning, customer management, and interconnect billing system. 4. User Segment that carries the function to interface satellite and terrestrial users to the Regional B-GAN system. the User Segment consists of the following: User Terminal or Mobile Satellite Unit (MSU) that will consist of Lap top or PC and a satellite modem terminal that connects the end user computing equipment to the satellite network. Mobile Internet via Satellite 33

35 Service Provider Point of Presence (SP POP) that provides access to the terrestrial packet data (GPRS) network or to Internet Service Provider (ISP). System interfaces: These units communicate with each other using two types of interfaces: 1. Communication interfaces: which support the range of network and user information capabilities. The communication interface that interconnect the four functional segments of the system are the following: The SAS-to-satellite interface. MSU-to-satellite interface(ai). The PoP-to-terrestrial network interface. The SAS-to-business support system(bss) interface. 2. Management interfaces: which support the provisioning, operation and management of the regional BGAN system. Coverage: The R-BGAN services will cover almost all of Europe, Northern and parts of Central Africa, Central Asia, the Middle East, and the Indian sub-continent. The BGAN services will cover almost 80% of the earth's landmass. To achieve this coverage and to offer these services, the covered area is covered using multiple spot beams and reusing frequency at different apart spot beams is used. Also, FDMA/TDMA radio access is used. Numbering: The users of the BGAN MSUs will be identified by two identifiers numbers. Firstly, the SIM card will have an IIN identifier, based on ITU-T recommendation E.118, from the DTI/RA organization. Secondly, the SIM will also carry, via the UK administration, an international mobile subscriber identification (IMSI) in accordance with ITU-T recommendation E.212. This report discusses also the requirements and steps of having access to this system. It also shows how the migration process, from the R-BGAN to the BGAN phase, will occur. Billing: Users will be charged for packet data services based upon the amount of information sent and received rather than the time for which they are connected. Emergency call handling: The countries can handle the emergency calls by making deals with the satellite service providers to have a single international format telephone number to which emergency calls may be directed from BGAN land mobile terminals. Fraud management: Inmarsat has taken into its consideration the telecom fraud problem and has tried to solve this problem by applying different methods including: Mobile Internet via Satellite 34

36 1. Deny access to a user whose position is determined to be within a jurisdiction where B-GAN services are not authorized. 2. Deactivation of users SIM cards on basis of the subscribers identity information provided by the country's National Authority Agent and/or the Law Enforcement Agency. 3. Using authentication methods and public key encryption. The report gives an overview about the different types of R-BGAN and BGAN products. MSU conformity standards: It also introduces the different standards that should be complied by the MSUs to be type approved. These standards are: The EMI Standards: ETSI EN v1.2.1 & ITU-R M.1480 The EMC Standards: ETSI EN & , EMC and Radio spectrum matters (ERM) The Safety Standards: CENELEC EN & IEEE c Legal interception (LI) of communications in B-GAN: it is the simultaneous gathering of data and information as they are created during a communication. To enable proper supervision of the interception of communications, a central control facility will be located in the Network Operation Centre (NOC) at the Inmarsat headquarters in London, UK. The BGAN LI architecture includes a component designed to be managed locally, the Remote Provisioning Unit (RPU). This unit makes it possible to input the information necessary for the interception of communications from the premises in a remote location. The RPU will be located with the license-holder in each country; however, depending on local regulations on security, it could also be located with regulator, Law Enforcement or other Security Agency. Mobile Internet via Satellite 35

37 18 Conclusion As a result of this technical study on the regional BGAN and BGAN systems, it would be worth to mention some points that should be taken into considerations when issuing the license for this service: 1. Identifying the type of interconnection that the distribution partner (DP) will choose to connect Inmarsat GPRS network with Internet, and identifying the number of links between the DP and internet cloud and BSS network, and their types. 2. Determining the ability of providing roaming with other mobile network operators by this DP to its customers. 3. Identifying MSUs providers for customers in Egypt. 4. Determining the minimum data rate that will be acquired by customers in worst cases(high traffic load). 5. Identifying Signal power levels in both uplink and downlink. 6. Identifying the billing system used and the cost of each service. 7. The authority can use Inmarsat fraud management system to block any unlicensed operators or to limit the access of some users. 8. B-GAN system architecture will include the functionality required to perform the legal interception(li) of communications on behalf of a legally entitled authority, normally referred as a Law Enforcement Agency(LEA), the authority can use this functionality to intercept any communications in B-GAN system. 9. Ensuring the provision of emergency call handling system. 10. Identifying numbering technique used and reserved numbers for provision of service in Egypt. 11. Identifying multiple access technique used in transmission. 12. Identifying different classes of service according to provided bit rates, identifying modulation and coding used. Mobile Internet via Satellite 36