Method and system for securing control packets and data packets in a mobile broadband network environment

The present invention provides a method and an apparatus for securing data packets and control messages in a mobile broadband network environment. In one embodiment, a mobile station and a data gateway are peers for securing data packets. That is, security context for data packets is maintained at the mobile station and the data gateway. Further, security processing for data packets is performed by the mobile station and the data gateway. In another embodiment, the mobile station and a base station are peers for securing control messages. That is, security context for control messages is maintained at the mobile station and the base station(s). Further, security processing for control messages is performed by the mobile station and the base station(s).

PRIORITY

This application claims the benefit under 35 U.S.C. §119(a) of an Indian patent application filed in the India Patent Office on Jun. 13, 2012 and assigned Serial No. 2378/CHE/2012, the entire disclosure of which is hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to the field of mobile broadband systems, and more particularly relates to securing control and data packets in a mobile broadband network environment.

2. Description of the Related Art

Recently, several broadband wireless technologies have been developed to meet growing number of broadband subscribers and to provide more and better applications and services. For example, 3rd Generation Partnership Project 2 (3GPP2) developed Code Division Multiple Access 2000 (CDMA 2000), 1×Evolution Data Optimized (1×EVDO) and Ultra Mobile Broadband (UMB) systems. The 3rd Generation Partnership Project (3GPP) developed Wideband Code Division Multiple Access (WCDMA), High Speed Packet Access (HSPA) and Long Term Evolution (LTE) systems. The Institute of Electrical and Electronics Engineers developed Mobile Worldwide Interoperability for Microwave Access (WiMAX) systems. As more and more people become users of mobile communication systems and more and more services are provided over these systems, there is an increasing need for mobile communication system with large capacity, high throughput, lower latency and better reliability.

Millimeter-Wave Mobile Broadband (MMB) system based on millimeter waves i.e., radio waves with wavelength in range of (millimeter (mm) to 10 mm, which corresponds to a radio frequency of 30 Gigahertz (GHz) to 300 GHz, is a candidate for next generation mobile communication technology as vast amount of spectrum is available in the mmWave band. Typically, an MMB system consists of multiple MMB base stations (BSs) that cover a geographic area. In order to ensure good coverage, MMB base stations need to be deployed with higher density than macro-cellular base stations. In general, roughly the same site-to-site distance as microcell or Pico-cell deployment in an urban environment is recommended. Transmission and/or reception in an MMB system are based on narrow beams which suppress interference from neighboring MMB base stations and extend range of an MMB link. This allows significant overlap of coverage among neighboring base stations.

Unlike cellular network systems that partition a geographic area into cells with each cell served by one or few base stations, the MMB base stations form a grid with a large number of nodes to which an MMB mobile station can communicate. The MMB base station grid eliminates the problem of poor link quality at the cell edge that is inherent in cellular network system and enables high-quality equal grade of service (EGOS) regardless of the location of a mobile station.

In order to utilize the fact that MS can detect signal from multiple MMB base stations in a MMB network, a cloud cell is formed around the MS. A cloud cell is a virtual cell consisting of multiple BSs that serve a single MS. The MMB BSs in a cloud cell communicating with the MS need to perform downlink (DL) Tx Beamforming, while the MS may need to perform DL Rx Beamforming to receive DL control and data. A MS communicating with a MMB BS in the cloud cell may need to perform uplink (UL) Tx Beamforming while the MMB BS may need to perform UL Rx Beamforming to transmit UL data.

In the traditional communication system wherein a MS communicates with single BS, BS receives Internet Protocol (IP) packets from a data gateway in DL direction, performs entire processing of IP packets, and transmits physical bursts carrying the processed IP packets to the MS. In UL direction, the BS receives physical bursts carrying IP packets from the MS, performs entire processing of the received physical burst and transmits the IP packets to the data gateway.

Typically, in order to secure the IP packets, the BS encrypts the IP packets received from the data gateway prior to transmitting to the MS. Similarly, the BS decrypts the IP packets received from the MS before transmitting to the data gateway. An authentication/authorization key (AK) is generated for an <MS, BS> pair. The AK is generated by key distribution function in the network and provided to a BS. MS also generates the AK. Independent security keys are then generated from the AK for control and data packets. <MS, BS> uses these generated security keys for control and data to apply security to control and data packets respectively. Authorization/Authentication key (AK) is updated when the MS performs handover from one BS to another.

The procedure and interaction between various entities to generate security keys is given below. At first, the MS registers with the BS and MS context (capability) is initialized with the authenticator. The MS is then authenticated with an AAA server using Extensible Authentication Procedure (EAP) procedures. As part of EAP procedure, Master Session Key (MSK) is established at the MS and an Authentication, Authorization and Accounting (AAA) server. The AAA server then transfers the MSK to the authenticator. Thereafter, the authenticator and the MS derive a Pair Wise Master Key (PMK) from the MSK. Then, the authenticator and the MS derive an authentication key specific to the BS from the PMK. The authenticator transfers the derived authentication to the BS. The BS and the MS derives security keys for data and control packets from the authentication key. In this procedure, the MSK is known to the MS, the authenticator and the AAA server. The MS receives the MSK from the AAA server during the EAP procedure. Also, the authenticator receives the MSK from the AAA server. The PMK is known to the MS and the authenticator. The PMK is derived by the MS and the authenticator from the MSK. The AK is known to the MS, the BS and the authenticator. The MS and the authenticator derive AK from the PMK. The BS receives the AK from the authenticator.

In another wireless communication system such as Long Term Evolution (LTE), where MS communicates with single BS, security processing for data packets is performed by MS and BS. However, control packets are divided in two categories, category 1 consists of control packets terminating at BS and category 2 consists of control packets terminating at Mobility Management Entity (MME). Security processing of control packets terminating at BS is done by MS and BS. Security processing of control packets terminating at MME is done by MS and MME.

In the mobile broadband system, where the multiple BSs are grouped together to serve a single MS and the MS communicates with multiple BSs in the cloud cell, several methods are proposed for security. In one method, each BS in a cloud cell is capable of applying security function on IP packets. Each BS applies security to IP packets received from the data gateway or the Master BS before transmitting to the MS. Each BS also applies security to the IP packets received from the MS before transmitting to the data gateway or the Master BS. However, this scheme requires either sharing of security keys to all BSs in the cloud cell or maintaining independent security keys for each BS. The sharing of security keys across the BSs in the cloud cell or maintaining independent security keys for each BS requires frequent update of the security keys due to addition or deletion of the BS(s) in the cloud cell. The BS(s) may be added and deleted frequently because of the small coverage area of each BS in the mobile broadband system.

In a mobile broadband system with gigabit throughput, in order to facilitate faster processing it is necessary that packets are already encrypted before resources for transmitting packets are allocated to MS by BS. The frequent key update may result in discarding of already encrypted packets at the MS. The MS also needs to maintain both encrypted and unencrypted packets in order to re-encrypt the packets after the security keys are updated. Independent security key for each BS may also require the MS to maintain multiple security keys which is not desirable to reduce the MS complexity.

In another scheme, only master BS may be allowed to apply security to packets received from the data gateway and the MS. This may also lead to frequent key update because of change of master BS. This also introduces an additional hop for the IP packets going through the BS other than master BS.

SUMMARY OF INVENTION

Aspects of the present invention are to address at least the above-mentioned problems and/or disadvantages and to provide at least the advantages described below. Accordingly, an aspect of the present invention is to provide a method and an apparatus for securing control packets and data packets in a mobile broadband network environment.

In accordance with an aspect of the present invention, a method for secured communication of data packets in a mobile broadband network environment is provided. The method comprises receiving one or more data packets intended for a mobile station from a packet data network by a data gateway, encrypting the one or more data packets using one or more security keys established at the data gateway for secured communication with the mobile station, and transmitting the encrypted one or more data packets to the mobile station via one or more base stations.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

The terms ‘control packets’ and ‘control messages’ are interchangeably used throughout the document.

FIG. 1is a schematic representation illustrating a mobile broadband network environment100, in the context of the invention. Referring toFIG. 1, the mobile broadband network environment100includes a packet data network102, a data gateway104, base stations106A-N and a mobile station108. In the mobile broadband network environment100, the base stations106A-N serving the mobile station108are connected to the data gateway104and configured for receiving data packets from the data gateway104and transmitting data packets to the data gateway104. Alternatively, the base stations106A-N serving the mobile station108are connected to the data gateway104while a master base station (e.g., the base station106A) is configured for receiving/transmitting data packets for the mobile station108from/to the data gateway104. In some embodiments, the base stations106A-N may be physically connected to the data gateway104. In other embodiments, the base stations106A-N may be logically connected to the data gateway104via other base stations or network nodes.

The data gateway104is an entity through which data packets transmitted to the mobile station108in downlink direction and data packets received from the mobile station108in uplink direction are routed. The data gateway104may be also known as access gateway or packet gateway in the art. The mobile station108may be a mobile phone capable of receiving and transmitting data packets/control messages from the data gateway104/base stations106A-N.

FIG. 2is a schematic representation illustrating another mobile broadband network environment200, in the context of the invention. It can be seen that the mobile broadband network environment200is similar to the mobile broadband network environment100ofFIG. 1, except that the master base station106A amongst the plurality of base stations106A-N serving the mobile station108can receive/transmit data packets for the mobile station108from/to data gateway104. It can be noted that, the master base station106A may be physically connected to the data gateway104or logically connected to the data gateway104via other base stations or network nodes.

According to the present invention, the mobile station108and the data gateway104are peers for securing data packets. That is, security context for data packets is maintained at the mobile station108and the data gateway104. Further, security processing for data packets is performed by the mobile station108and the data gateway104. Since, the data gateway104is peer for securing data packets, one or more data security keys for securing data packets is not required to be updated till the mobile station108moves away from the base stations106A-N to another base station(s) which is not connected to the data gateway104. Further, the mobile station108and the base stations106A-N are peers for securing control messages. That is, security context for control messages is maintained at the mobile station108and the base stations106A-N. Further, security processing for control messages is performed by the mobile station108and the base stations106A-N.

FIG. 3Aillustrates a block diagram300of various entities of a wireless network system involved in secured communication of data packets/control messages, according to one embodiment. The various entities involved in secured communication of data packets include the mobile station108and the data gateway104. Similarly, the various entities involved in secured communication of control messages include the mobile station108and the base station106.

Referring toFIG. 3A, the mobile station108includes a data packet security module302and a control packet security module304. The data packet security module302is configured for generating a data authentication/authorization key (AKdata) using an identifier of the mobile station108, an identifier of the data gateway104, and one of pair wise master key (PMK) and master session key (MSK). In one exemplary implementation, the identifier of the data gateway104is received by the mobile station108from the mobile broadband network. The PMK is generated from the MSK, where the MSK is established between the mobile station108and an Authentication, Authorization and Accounting (AAA) server during an authentication procedure. The authentication procedure is generally performed when the mobile station108registers with the mobile broadband network. Alternatively, the authentication procedure may be performed upon expiry of life time of the master session key. In an exemplary implementation, few bits of the MSK are truncated to generate the PMK.

Further, the data packet security module302is configured for generating one or more data security keys using the data authorization/authentication key. Alternatively, the data packet security module302is configured for generating one or more data security keys using the identifier of the mobile station108, the identifier of the data gateway104, and one of the PMK and the MSK established or derived at the mobile station108during the authentication procedure.

Furthermore, the data packet security module302is configured for encrypting data packets and decrypting encrypted data packets using the one or more generated data security keys. In one exemplary implementation, the data packet security module302encrypts/decrypts data packets by applying privacy protection to the data packets using the one or more data security keys. In another exemplary implementation, the data packet security module302encrypts/decrypts data packets by applying integrity protection to the data packets using the one or more data security keys. In yet another exemplary implementation, the data packet security module302encrypts/decrypts data packets by applying privacy protection to the data packets and integrity protection to the data packets using the one or more data security keys.

The control packet security module304is configured for generating a control authentication/authorization key (AKcontrol) for generating one or more control security keys. In one embodiment, the control packet security module304is configured for generating the control authentication/authorization key using an identifier of the mobile station108, an identifier of the master base station106A, and one of the PMK and the MSK. In another embodiment, the control packet security module304is configured for generating the control authentication/authorization key using an identifier of the mobile station108, an identifier of the cloud cell to which the mobile station108belongs, and one of the PMK and the MSK. In yet another embodiment, the control packet security module304is configured for generating the control authentication/authorization key using an identifier of the mobile station108, an identifier of respective base station in the cloud cell associated with the mobile station108, and one of the PMK and the MSK. In further another embodiment, the control packet security module304is configured for generating the control authentication/authorization key using an identifier of the mobile station108, a random seed in the cloud cell associated with the mobile station108, and one of the PMK and the MSK.

Further, the control packet security module304is configured for generating one or more control security keys using the control authentication/authorization key. Furthermore, the control packet security module304is configured for encrypting control messages and decrypting encrypted control messages using the one or more control security keys. In one exemplary implementation, the control packet security module304encrypts/decrypts control message by applying privacy protection to the control message using the one or more control security keys. In another exemplary implementation, the control packet security module304encrypts/decrypts control message by applying integrity protection to the control message using the control security keys. In yet another exemplary implementation, the control packet security module304encrypts/decrypts control message by applying privacy protection to the control message and integrity protection to the control message using the control security keys.

The hierarchy of keys generated at the mobile station by the data packet security module302and the control packet security module304is illustrated inFIGS. 12A-12D.

The base station106includes a control packet security module306. The control packet security module306is configured for generating a control authentication/authorization key for generating one or more control security keys. In one embodiment, the control packet security module306is configured for generating the control authentication/authorization key using an identifier of the mobile station108, an identifier of the master base station106A, and one of the PMK and the MSK. In another embodiment, the control packet security module304is configured for generating the control authentication/authorization key using an identifier of the mobile station108, an identifier of the cloud cell to which the mobile station108belongs, and one of the PMK and the MSK. In yet another embodiment, the control packet security module304is configured for generating the control authentication/authorization key using an identifier of the mobile station108, an identifier of respective base station in the cloud cell associated with the mobile station108, and one of the PMK and the MSK. Alternatively, the control authentication key is directly received from the authenticator for generating one or more control security keys. Further, the control packet security module306is configured for generating one or more control security keys using the control authentication/authorization key.

Furthermore, the control packet security module306is configured for encrypting control messages and decrypting encrypted control messages using the one or more generated control security keys. In one exemplary implementation, the control packet security module306encrypts/decrypts control messages by applying privacy protection to the control message using the one or more control security keys. In another exemplary implementation, the control packet security module306encrypts/decrypts control messages by applying integrity protection to the control message using the one or more control security keys. In yet another exemplary implementation, the control packet security module306encrypts/decrypts control message by applying privacy protection to the control messages and integrity protection to the control messages using the one or more control security keys.

The data gateway104includes a data packet security module308. The data packet security module308is configured for receiving one of the PMK and the MSK from an authenticator (e.g., AAA server) and generating a data authentication/authorization key using an identifier of the mobile station108, an identifier of the data gateway104, and the one of the PMK and the MSK. Alternatively, the data authentication/authorization key is received from the authenticator. Further, the data packet security module308is configured for generating one or more data security keys using the data authentication/authorization key. Alternatively, the data packet security module308is configured for receiving one of pair wise master key and master session key from an authenticator (e.g., AAA server) and generating one or more data security keys using the identifier of the mobile station108, the identifier of the data gateway104, and the one of the PMK and the MSK. In some embodiments, the one or more data security keys may be directly received from the authenticator.

Furthermore, the data packet security module308is configured for encrypting data packets received from the packet data network102and decrypting the encrypted data packets received from the mobile station108using the one or more data security keys. In one exemplary implementation, the data packet security module308encrypts/decrypts data packets by applying privacy protection to the data packets using the one or more data security keys. In another exemplary implementation, the data packet security module308encrypts/decrypts data packets by applying integrity protection to the data packets using the one or more data security keys. In yet another exemplary implementation, the data packet security module308encrypts/decrypts data packets by applying privacy protection to the data packets and integrity protection to the data packets using the one or more data security keys.

FIG. 3Billustrates a block diagram350of various entities of a wireless network system involved in secured communication of data packets/control messages, according to another embodiment. It can be seen that the block diagram350is same as the block diagram300ofFIG. 3A, except the entities involved in secured communication of control messages. The entities involved in secured communication of control messages include the mobile station108, the base station106, the data gateway104, and a mobility management entity352. The mobile station108includes a control packet security module354and a control packet security module356. The control packet security module354is configured for encrypting/decrypting control messages intended for the base station106using first set of control security keys. The first set of control security keys are generated by the control packet security module354or received from the authenticator. The control packet security module356is configured for encrypting/decrypting control messages intended for the mobility management entity352using a second set of control security keys. The second set of security keys are generated by the control packet security module356or received from the authenticator.

The mobility management module352includes a control packet security module358. The control packet security module358is configured for encrypting control messages intended for the mobile station108and decrypting control messages received from the mobile station108using a second set of security keys established at the mobility management entity352.

One skilled in the art will understand that, the mobile station108and the data gateway104can continue to use data security keys derived from data authentication keys even if the mobile station108performs handover from one base station to another or a base station is added or deleted from a cloud cell due to mobility of the mobile station108.

One skilled in the art will also understand that, if the control authentication key is generated based on a cloud seed (i.e., identifier of a cloud cell), then a new control authentication key is to be generated when a new base station is added to the cloud cell or the existing base station deleted from the cloud cell.

If the control authentication key is generated based on identifier of a master base station, then the control authentication key is to be updated when the master base station is changed. If the control authentication key is generated based on identifier of a base station, then a new control authentication key and associated control security keys is to be derived for a new base station added in the cloud cell. Similarly, if the control authentication key is generated based on identifier of a base station then the control authentication key and associated control security keys is to be deleted for a base station deleted from the cloud cell.

FIG. 4Ais a flow diagram400illustrating an exemplary method of securely communicating data packets from the mobile station108to the data gateway104, according to one embodiment. When the mobile station108wishes to transmit data to the packet data network102, the mobile station108generates data packets402carrying the data, at step402.

At step404, the mobile station108encrypts the data packets using one or more data security keys established at the mobile station108. At step406, the mobile station108transmits MAC PDU(s) carrying the encrypted data packets to the master base station106A. In one embodiment, the MAC PDU(s) carries unfragmented data packets. In another embodiment, the MAC PDU(s) carries fragmented data packets.

At step408, the master base station106A unpacks the encrypted data packets from the received MAC PDU(s). At step410, the master base station106A transmits the unfragmented encrypted data packets to the data gateway104. At step412, the data gateway104decrypts the encrypted data packets using one or more data security keys established at the data gateway104. At step414, the data gateway104transmits the decrypted data packets to the packet data network102for further processing.

FIG. 4Bis a flow diagram450illustrating an exemplary method of securely communicating data packets from the mobile station108to the data gateway104, according to another embodiment. At step452, the mobile station108generates data packets carrying data to be transmitted to the packet data network102. At step454, the mobile station108encrypts the data packets using one or more data security keys established at the mobile station108. At step456, the mobile station108transmits MAC PDU(s) carrying the encrypted data packets to the slave base station106B. In one embodiment, the MAC PDU(s) carries unfragmented data packets. In another embodiment, the MAC PDU(s) carries fragmented data packets. At step458, the slave base station106B transmits the MAC PDU(s) carrying the encrypted data packets to the master base station106A.

At step460, the master base station106A unpacks the encrypted data packets from the received MAC PDU(s). At step462, the master base station106A transmits the unfragmented encrypted data packets to the data gateway104. At step464, the data gateway104decrypts the encrypted data packets using one or more data security keys established at the data gateway104for transmitting the decrypted data packets to the packet data network102for further processing.

FIG. 4Cis a flow diagram470illustrating an exemplary method of securely communicating data packets from the mobile station108to the data gateway104, according to yet another embodiment. At step472, the mobile station108generates data packets carrying data for the packet data network102. At step474, the mobile station108encrypts the data packets using one or more data security keys established at the mobile station108.

At step476, the mobile station108transmits MAC PDU(s) carrying the encrypted data packets to the master base station106A. In one embodiment, the MAC PDU(s) carries unfragmented data packets. In another embodiment, the MAC PDU(s) carries fragmented data packets. At step478, the master base station106A unpacks the encrypted data packets from the received MAC PDU(s). At step480, the master base station106A transmits the unfragmented encrypted data packets to the data gateway104.

Substantially simultaneously, at step482, the mobile station108transmits MAC PDU(s) carrying the encrypted data packets to the slave base station106B. At step484, the slave base station106B unpacks the encrypted data packets from the received MAC PDU(s). At step486, the slave base station106B transmits the unfragmented encrypted data packets to the data gateway104. At step488, the data gateway104decrypts the encrypted data packets received from the master base station106A and/or the slave base station106B using one or more data security keys established at the data gateway104.

FIG. 5Ais a flow diagram500illustrating an exemplary method of securely communicating control packets from the mobile station108to the master base station106A, according to one embodiment. When the mobile station108wishes to securely transmit control information to the master mobile station106A, the mobile station108generates a control message containing control information, at step502. At step504, the mobile station108encrypts the control message using one or more control security keys established at the mobile station108for secured communication of control messages.

At step506, the mobile station108transmits MAC PDU(s) carrying the encrypted control message to the master base station106A. In one embodiment, the MAC PDU(s) carries unfragmented control message. In another embodiment, the MAC PDU(s) carries fragmented control message. At step508, the master base station106A unpacks the encrypted control message from the MAC PDU(s). At step510, the master base station106A decrypts the encrypted control message using one or more control security keys established at the master base station106A.

FIG. 5Bis a flow diagram550illustrating an exemplary method of securely communicating control packets from the mobile station108to the master base station106A, according to another embodiment. At step552, the mobile station108generates a control message containing control information. At step554, the mobile station108encrypts the control message using one or more control security keys established at the mobile station108for secured communication of control messages.

At step556, the mobile station108transmits MAC PDU(s) carrying the encrypted control message to the slave base station106B. In one embodiment, the MAC PDU(s) carries unfragmented control message. In another embodiment, the MAC PDU(s) carries fragmented control message. At step558, the slave base station106B transmits the MAC PDU(s) carrying the encrypted control message to the master base station106A. At step560, the master base station106A unpacks the encrypted control message from the MAC PDU(s). At step562, the master base station106A decrypts the encrypted control message using one or more control security keys established at the master base station106A.

FIG. 5Cis a flow diagram570illustrating an exemplary method of securely communicating control packets from the mobile station108to the master base station106A and the slave base station106B, according to yet another embodiment. At step572, the mobile station108generates a control message containing control information. At step574, the mobile station108encrypts the control message using one or more control security keys established at the mobile station108for secured communication of control messages.

At step576, the mobile station108transmits MAC PDU(s) carrying the encrypted control message to the master base station106A and the slave base station106B. In one embodiment, the MAC PDU(s) carries unfragmented control message. In another embodiment, the MAC PDU(s) carries fragmented control message. At step578, the master base station106A unpacks the encrypted control message from the MAC PDU(s). At step580, the master base station106A decrypts the encrypted control message using one or more control security keys established at the master base station106A. Similarly, at step582, the slave base station106B unpacks the encrypted control message from the MAC PDU(s). At step584, the slave base station106B decrypts the encrypted control message using one or more control security keys established at the slave base station106B.

FIG. 6Ais a flow diagram600illustrating an exemplary method of securely communicating data packets from the data gateway104to the mobile station108, according to one embodiment. At step602, the data gateway104receives data packets intended for the mobile station108from the packet data network102. At step604, the data gateway104encrypts the data packets using one or more data security keys established at the data gateway104. At step606, the data gateway104transmits the unfragmented encrypted data packets to the master base station106A.

At step608, the master base station106A transmits MAC PDU(s) carrying the encrypted data packets to the mobile station108. In one embodiment, the MAC PDU(s) carries unfragmented data packets. In another embodiment, the MAC PDU(s) carries fragmented data packets. At step610, the mobile station108unpacks the encrypted data packets from the received MAC PDU(s). At step612, the mobile station108decrypts the encrypted data packets using one or more data security keys established at the mobile station102.

FIG. 6Bis a flow diagram650illustrating an exemplary method of securely communicating data packets from the data gateway104to the mobile station108, according to another embodiment. When the data gateway104receives data packets intended for the mobile station108from the packet data network102, at step652, the data gateway104encrypts the data packets using one or more data security keys established at the data gateway104. At step654, the data gateway104transmits the unfragmented encrypted data packets to the master base station106A.

At step656, the master base station106A transmits MAC PDU(s) carrying the encrypted data packets to the slave base station106B. In one embodiment, the MAC PDU(s) carries unfragmented data packets. In another embodiment, the MAC PDU(s) carries fragmented data packets. At step658, the slave base station106B transmits the MAC PDU(s) carrying the encrypted data packets to the mobile station108. At step660, the mobile station108unpacks the encrypted data packets from the received MAC PDU(s). At step662, the mobile station108decrypts the encrypted data packets using one or more data security keys established at the mobile station102.

FIG. 6Cis a flow diagram670illustrating an exemplary method of securely communicating data packets from the data gateway104to the mobile station108, according to yet another embodiment. When the data gateway104receives data packets intended for the mobile station108from the packet data network102, at step672, the data gateway104encrypts the data packets using one or more data security keys established at the data gateway104. At step674, the data gateway104transmits the unfragmented encrypted data packets to the master base station106A. Also, at step676, the data gateway104transmits the unfragmented encrypted data packets to the slave base station106B.

At step678, the master base station106A transmits MAC PDU(s) carrying the encrypted data packets to the mobile station108. In one embodiment, the MAC PDU(s) carries unfragmented data packets. In another embodiment, the MAC PDU(s) carries fragmented data packets. Additionally, at step680, the master base station106A transmits control information to the slave base station106B. The control information indicates the slave base station1068that the encrypted data packets are to be directly transmitted to the mobile station108.

At step682, the slave base station106B transmits the MAC PDU(s) carrying the encrypted data packets to the mobile station108based on the control information. In one embodiment, the MAC PDU(s) carries unfragmented data packets. In another embodiment, the MAC PDU(s) carries fragmented data packets. At step684, the mobile station108unpacks the encrypted data packets from the received MAC PDU(s). At step686, the mobile station108decrypts the encrypted data packets using one or more data security keys established at the mobile station102. In some embodiments, the mobile station108may unpack and decrypt the encrypted data packets received from the master base station106A or the slave base station106B.

FIG. 7Ais a flow diagram700illustrating an exemplary method of securely communicating control packets from the master base station106A to the mobile station108, according to one embodiment. When the master base station106A wishes to securely transmit control information to the mobile station108, the master base station106A generates a control message containing control information, at step702. At step704, the master base station106A encrypts the control message using one or more control security keys established at the master base station106A for secured communication of control messages.

At step706, the master base station106A transmits MAC PDU(s) carrying the encrypted control message to the mobile station108. In one embodiment, the MAC PDU(s) carries unfragmented control message. In another embodiment, the MAC PDU(s) carries fragmented control message. At step708, the mobile station108unpacks the encrypted control message from the MAC PDU(s). At step710, the mobile station108decrypts the encrypted control message using one or more control security keys established at the mobile station108.

FIG. 7Bis a flow diagram750illustrating an exemplary method of securely communicating control packets from the master base station106A to the mobile station108, according to another embodiment. At step752, the master base station106A generates a control message containing control information. At step754, the master base station106A encrypts the control message using one or more control security keys established at the master base station106A for secured communication of control messages.

At step756, the master base station106A transmits MAC PDU(s) carrying the encrypted control message to the slave base station106B. In one embodiment, the MAC PDU(s) carries unfragmented control message. In another embodiment, the MAC PDU(s) carries fragmented control message. At step758, the slave base station106B transmits the MAC PDU(s) carrying the encrypted control message to the mobile station108. At step760, the mobile station108unpacks the encrypted control message from the MAC PDU(s). At step762, the mobile station108decrypts the encrypted control message using one or more control security keys established at the mobile station108.

FIG. 7Cis a flow diagram770illustrating an exemplary method of securely communicating control packets from the master base station106A and the slave base station106B to the mobile station108, according to yet another embodiment. At step772, the master base station106A generates a control message carrying control information intended for the mobile station108. At step774, the master base station106A encrypts the control message using one or more control security keys established at the master base station106A. At step776, the master base station106A transmits MAC PDU(s) carrying the encrypted control message to the mobile station108. In one embodiment, the MAC PDU(s) carries unfragmented control message. In another embodiment, the MAC PDU(s) carries fragmented control message.

At step778, the master base station106A transmits control information to the slave base station106B. The control information indicates that the slave base station106B needs to transmit the encrypted control message to the mobile station108. Accordingly, at step780, the slave base station106B generates a control message carrying the control information. At step782, the slave base station106B encrypts the control message using one or more control security keys established at the slave base station106B. At step784, the slave base station106B transmits MAC PDU(s) carrying the encrypted control message to the mobile station108. In one embodiment, the MAC PDU(s) carries unfragmented control message. In another embodiment, the MAC PDU(s) carries fragmented control message. At step786, the mobile station108unpacks the encrypted control message from the MAC PDU(s) received from the master base station106A or the slave base station106B. At step788, the mobile station108decrypts the encrypted control message using one or more control security keys established at the mobile station108.

FIG. 8is a process flowchart800illustrating an exemplary method of processing MAC PDU(s) received from the mobile station108, according to one embodiment. The process steps802to814are performed by the master base station106A or the slave base station106B of a cloud cell to which a mobile station belongs.

At step802, MAC PDU(s) is received from the mobile station108. At step804, it is determined whether the received MAC PDU(s) carry encrypted control message. If the received MAC PDU(s) does not carry encrypted control message, then it implies that the MAC PDU(s) carry encrypted data packets. Thus, at step806, the encrypted data packets are unpacked from the MAC PDU(s) and transmitted to the data gateway104for further processing. However, if, at step804, it is determined that the MAC PDU(s) does not carry the encrypted control message, then at step808, it is determined whether the base station of the cloud cell to which the mobile station108belongs is a master base station.

If the base station is not a master base station, then at step810, the MAC PDU(s) carrying the encrypted control message is transmitted to the master base station. If the base station is a master base station, then at step812, the encrypted control message is unpacked from the MAC PDU(s). Further, at step814, the encrypted control message is decrypted using one or more control security keys established at the base station for further processing. It can be noted that, when the master base station and the slave base station are configured for receiving encrypted control message and decrypting the encrypted control message, the base station may skip the step808and directly unpack and decrypt the encrypted control message as indicated through a dotted arrow line.

FIG. 9is a block diagram of the data gateway104showing various components for implementing embodiments of the present subject matter. Referring toFIG. 9, the data gateway104includes a processor902, a memory904, a read only memory (ROM)906, a transceiver908, and a bus910.

The processor902, as used herein, means any type of computational circuit, such as, but not limited to, a microprocessor, a microcontroller, a complex instruction set computing microprocessor, a reduced instruction set computing microprocessor, a very long instruction word microprocessor, an explicitly parallel instruction computing microprocessor, a graphics processor, a digital signal processor, or any other type of processing circuit. The processor902may also include embedded controllers, such as generic or programmable logic devices or arrays, application specific integrated circuits, single-chip computers, smart cards, and the like.

The memory904and the ROM906may be volatile memory and non-volatile memory. The memory904includes a data packet security module308for generating one or more data security keys, encrypting data packets intended for a mobile station and decrypting data packets received from a mobile station using the one or more data security keys, according to one or more embodiments described above. A variety of computer-readable storage media may be stored in and accessed from the memory elements. Memory elements may include any suitable memory device(s) for storing data and machine-readable instructions, such as read only memory, random access memory, erasable programmable read only memory, electrically erasable programmable read only memory, hard drive, removable media drive for handling compact disks, digital video disks, diskettes, magnetic tape cartridges, memory cards, and the like.

Embodiments of the present subject matter may be implemented in conjunction with modules, including functions, procedures, data structures, and application programs, for performing tasks, or defining abstract data types or low-level hardware contexts. The data packet security module308may be stored in the form of machine-readable instructions on any of the above-mentioned storage media and may be executed by the processor902. For example, a computer program may include machine-readable instructions which when executed by the processor902, may cause the processor902to generate one or more data security keys, encrypt data packets intended for the mobile station108using the one or more data security keys and decrypt data packets received from a mobile station using the one or more data security keys, according to the teachings and herein described embodiments of the present subject matter. In one embodiment, the program may be included on a compact disk-read only memory (CD-ROM) and loaded from the CD-ROM to a hard drive in the non-volatile memory.

The transceiver908may be capable of transmitting encrypted data packets and receiving encrypted data packets. The bus910acts as interconnect between various components of the data gateway104.

FIG. 10is a block diagram of the base station106showing various components for implementing embodiments of the present subject matter. Referring toFIG. 10, the base station106includes a processor1002, a memory1004, a read only memory (ROM)1006, a transceiver1008, and a bus1010.

The processor1002, as used herein, means any type of computational circuit, such as, but not limited to, a microprocessor, a microcontroller, a complex instruction set computing microprocessor, a reduced instruction set computing microprocessor, a very long instruction word microprocessor, an explicitly parallel instruction computing microprocessor, a graphics processor, a digital signal processor, or any other type of processing circuit. The processor1002may also include embedded controllers, such as generic or programmable logic devices or arrays, application specific integrated circuits, single-chip computers, smart cards, and the like.

The memory1004and the ROM1006may be volatile memory and non-volatile memory. The memory1004includes a control packet security module306for generating one or more control security keys, encrypting control messages intended for the mobile station108and decrypting control message received from the mobile station108using the one or more control security keys, according to one or more embodiments described above. A variety of computer-readable storage media may be stored in and accessed from the memory elements. Memory elements may include any suitable memory device(s) for storing data and machine-readable instructions, such as read only memory, random access memory, erasable programmable read only memory, electrically erasable programmable read only memory, hard drive, removable media drive for handling compact disks, digital video disks, diskettes, magnetic tape cartridges, memory cards, and the like.

Embodiments of the present subject matter may be implemented in conjunction with modules, including functions, procedures, data structures, and application programs, for performing tasks, or defining abstract data types or low-level hardware contexts. The control packet security module306may be stored in the form of machine-readable instructions on any of the above-mentioned storage media and may be executed by the processor1002. For example, a computer program may include machine-readable instructions which when executed by the processor1002, may cause the processor1002to generate one or more control security keys, encrypt control messages intended for the mobile station108and decrypt control message received from the mobile station108using the one or more control security keys, according to the teachings and herein described embodiments of the present subject matter. In one embodiment, the program may be included on a compact disk-read only memory (CD-ROM) and loaded from the CD-ROM to a hard drive in the non-volatile memory.

The transceiver1008may be capable of transmitting MAC PDU(s) carrying encrypted data packets/encrypted control message to the mobile station108and receiving MAC PDU(s) carrying encrypted data packets/encrypted control message from the mobile station108. Also, the transceiver1008may be capable of transmitting encrypted data packets to the data gateway104and receiving encrypted data packets from the data gateway104. The bus1010acts as interconnect between various components of the base station106.

FIG. 11is a block diagram of the mobile station108showing various components for implementing embodiments of the present subject matter. ReferringFIG. 11, the mobile station108includes a processor1102, memory1104, a read only memory (ROM)1106, a transceiver1108, a bus1110, a display1112, an input device1114, and a cursor control1116.

The processor1102, as used herein, means any type of computational circuit, such as, but not limited to, a microprocessor, a microcontroller, a complex instruction set computing microprocessor, a reduced instruction set computing microprocessor, a very long instruction word microprocessor, an explicitly parallel instruction computing microprocessor, a graphics processor, a digital signal processor, or any other type of processing circuit. The processor1102may also include embedded controllers, such as generic or programmable logic devices or arrays, application specific integrated circuits, single-chip computers, smart cards, and the like.

The memory1104and the ROM1106may be volatile memory and non-volatile memory. The memory1104includes a data packet security module302for generating one or more data security keys, encrypting data packets intended for a mobile station and decrypting data packets received from a mobile station using one or more data security keys, and a control packet security module304for generating one or more control security keys, encrypting control messages intended for a mobile station and decrypting control message received from a mobile station using the one or more control security keys, according to one or more embodiments described above. A variety of computer-readable storage media may be stored in and accessed from the memory elements. Memory elements may include any suitable memory device(s) for storing data and machine-readable instructions, such as read only memory, random access memory, erasable programmable read only memory, electrically erasable programmable read only memory, hard drive, removable media drive for handling compact disks, digital video disks, diskettes, magnetic tape cartridges, memory cards, and the like.

Embodiments of the present subject matter may be implemented in conjunction with modules, including functions, procedures, data structures, and application programs, for performing tasks, or defining abstract data types or low-level hardware contexts. The data packet security module302and the control packet security module304may be stored in the form of machine-readable instructions on any of the above-mentioned storage media and may be executed by the processor1102. For example, a computer program may include machine-readable instructions, that when executed by the processor1102, cause the processor1102to encrypt data packets/control messages and decrypt data packets/control messages, according to the teachings and herein described embodiments of the present subject matter. In one embodiment, the computer program may be included on a compact disk-read only memory (CD-ROM) and loaded from the CD-ROM to a hard drive in the non-volatile memory.

The transceiver1108may be capable of transmitting MAC PDU(s) carrying encrypted data packets/encrypted control message to the base station106and receiving MAC PDU(s) carrying encrypted data packets/encrypted control message from the base station106. The bus1110acts as interconnect between various components of the mobile station108. The components such as the display1112, the input device1114, and the cursor control1116are well known to the person skilled in the art and hence the explanation is thereof omitted.

The present embodiments have been described with reference to specific example embodiments; it will be evident that various modifications and changes may be made to these embodiments without departing from the broader spirit and scope of the various embodiments. Furthermore, the various devices, modules, and the like described herein may be enabled and operated using hardware circuitry, for example, complementary metal oxide semiconductor based logic circuitry, firmware, software and/or any combination of hardware, firmware, and/or software embodied in a machine readable medium. For example, the various electrical structure and methods may be embodied using transistors, logic gates, and electrical circuits, such as application specific integrated circuit.