/* (C) 2018 by sysmocom s.f.m.c. GmbH * * Author: Stefan Sperling * * All Rights Reserved * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU Affero General Public License as published by * the Free Software Foundation; either version 3 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU Affero General Public License for more details. * * You should have received a copy of the GNU Affero General Public License * along with this program. If not, see . * */ #pragma once #include #include #include #include /*! * Access control class (ACC) ramping is used to slowly make the cell available to * an increasing number of MS. This avoids overload at startup time in cases where * a lot of MS would discover the new cell and try to connect to it all at once. */ #define ACC_RAMP_STEP_SIZE_MIN 1 /* allow at most 1 new ACC per ramp step */ #define ACC_RAMP_STEP_SIZE_DEFAULT ACC_RAMP_STEP_SIZE_MIN #define ACC_RAMP_STEP_SIZE_MAX 10 /* allow all ACC in one step (effectively disables ramping) */ #define ACC_RAMP_STEP_INTERVAL_MIN 30 /* 30 seconds */ #define ACC_RAMP_STEP_INTERVAL_MAX 600 /* 10 minutes */ /*! * Data structure used to manage ACC ramping. Please avoid setting or reading fields * in this structure directly. Use the accessor functions below instead. */ struct acc_ramp { struct gsm_bts *bts; /*!< backpointer to BTS using this ACC ramp */ bool acc_ramping_enabled; /*!< whether ACC ramping is enabled */ /*! * Bitmask which keeps track of access control classes that are currently denied * access. The function acc_ramp_apply() uses this mask to modulate bits from * octets 2 and 3 in RACH Control Parameters (see 3GPP 44.018 10.5.2.29). * Ramping is only concerned with ACCs 0-9. While any of the bits 0-9 is set, * the corresponding ACC is barred. * ACCs 11-15 should always be allowed, and ACC 10 denies emergency calls for * all ACCs from 0-9 inclusive; these ACCs are ignored in this implementation. */ uint16_t barred_accs; /*! * This controls the maximum number of ACCs to allow per ramping step (1 - 10). * The compile-time default value is ACC_RAMP_STEP_SIZE_DEFAULT. * This value can be changed by VTY configuration. * A value of ACC_RAMP_STEP_SIZE_MAX effectively disables ramping. */ unsigned int step_size; /*! * Ramping step interval in seconds. * This value depends on the current BTS channel load average, unless * it has been overridden by VTY configuration. */ unsigned int step_interval_sec; bool step_interval_is_fixed; struct osmo_timer_list step_timer; }; /*! * Enable or disable ACC ramping. * When enabled, ramping begins once acc_ramp_start() is called. * When disabled, an ACC ramping process in progress will continue * unless acc_ramp_abort() is called as well. * \param[in] acc_ramp Pointer to acc_ramp structure. */ static inline void acc_ramp_set_enabled(struct acc_ramp *acc_ramp, bool enable) { acc_ramp->acc_ramping_enabled = enable; } /*! * Return true if ACC ramping is currently enabled, else false. * \param[in] acc_ramp Pointer to acc_ramp structure. */ static inline bool acc_ramp_is_enabled(struct acc_ramp *acc_ramp) { return acc_ramp->acc_ramping_enabled; } /*! * Return the current ACC ramp step size. * \param[in] acc_ramp Pointer to acc_ramp structure. */ static inline unsigned int acc_ramp_get_step_size(struct acc_ramp *acc_ramp) { return acc_ramp->step_size; } /*! * Return the current ACC ramp step interval (in seconds) * \param[in] acc_ramp Pointer to acc_ramp structure. */ static inline unsigned int acc_ramp_get_step_interval(struct acc_ramp *acc_ramp) { return acc_ramp->step_interval_sec; } /*! * If the step interval is dynamic, return true, else return false. * \param[in] acc_ramp Pointer to acc_ramp structure. */ static inline bool acc_ramp_step_interval_is_dynamic(struct acc_ramp *acc_ramp) { return !(acc_ramp->step_interval_is_fixed); } /*! * Return bitmasks which correspond to access control classes that are currently * denied access. Ramping is only concerned with those bits which control access * for ACCs 0-9, and any of the other bits will always be set to zero in these masks, i.e. * it is safe to OR these bitmasks with the corresponding fields in struct gsm48_rach_control. * \param[in] acc_ramp Pointer to acc_ramp structure. */ static inline uint8_t acc_ramp_get_barred_t2(struct acc_ramp *acc_ramp) { return ((acc_ramp->barred_accs >> 8) & 0x03); }; static inline uint8_t acc_ramp_get_barred_t3(struct acc_ramp *acc_ramp) { return (acc_ramp->barred_accs & 0xff); } /*! * Potentially mark certain Access Control Classes (ACCs) as barred in accordance to ACC ramping. * \param[in] rach_control RACH control parameters in which barred ACCs will be configured. * \param[in] acc_ramp Pointer to acc_ramp structure. */ static inline void acc_ramp_apply(struct gsm48_rach_control *rach_control, struct acc_ramp *acc_ramp) { rach_control->t2 |= acc_ramp_get_barred_t2(acc_ramp); rach_control->t3 |= acc_ramp_get_barred_t3(acc_ramp); } void acc_ramp_init(struct acc_ramp *acc_ramp, struct gsm_bts *bts); int acc_ramp_set_step_size(struct acc_ramp *acc_ramp, unsigned int step_size); int acc_ramp_set_step_interval(struct acc_ramp *acc_ramp, unsigned int step_interval); void acc_ramp_set_step_interval_dynamic(struct acc_ramp *acc_ramp); void acc_ramp_trigger(struct acc_ramp *acc_ramp); void acc_ramp_abort(struct acc_ramp *acc_ramp);